Find a GP. for which sum of first two terms is –4 and fifth te

Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.
Advertisement

 Multiple Choice QuestionsShort Answer Type

111. If a, b, c, d are in GP., show that (a2 + b2 + c2) (b2 + c2 + d2) = (ab + bc + cd)2
135 Views

 Multiple Choice QuestionsLong Answer Type

112.

If a, b, c are in G.P. and x, y are the arithmetic means of a, b and b, c respectively,

then prove that   straight a over straight x plus straight c over straight y equals 2 and space space 1 over straight x plus 1 over straight y equals 2 over straight b

171 Views

 Multiple Choice QuestionsShort Answer Type

113.

If a, b, c are in A.P. and x,y,z are in G.P., show that 

straight x to the power of straight b minus straight c end exponent. space straight y to the power of straight c minus straight a end exponent. space straight z to the power of straight a minus straight b end exponent space equals space 1


138 Views

Advertisement

114. Find a GP. for which sum of first two terms is –4 and fifth term is 4 times the 3rd term.


Let the G.P. be a, ar, ar2, ..........

Given          a + ar = -4                                                                        ...(i)

Also,             <pre>uncaught exception: <b>mkdir(): Permission denied (errno: 2) in /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/util/sys/Store.class.php at line #56mkdir(): Permission denied</b><br /><br />in file: /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/util/sys/Store.class.php line 56<br />#0 [internal function]: _hx_error_handler(2, 'mkdir(): Permis...', '/home/config_ad...', 56, Array)
#1 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/util/sys/Store.class.php(56): mkdir('/home/config_ad...', 493)
#2 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/FolderTreeStorageAndCache.class.php(110): com_wiris_util_sys_Store->mkdirs()
#3 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/RenderImpl.class.php(231): com_wiris_plugin_impl_FolderTreeStorageAndCache->codeDigest('mml=<math xmlns...')
#4 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/TextServiceImpl.class.php(59): com_wiris_plugin_impl_RenderImpl->computeDigest(NULL, Array)
#5 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/service.php(19): com_wiris_plugin_impl_TextServiceImpl->service('mathml2accessib...', Array)
#6 {main}</pre>

or                space space space ar to the power of 5 minus 1 end exponent equals space 4. space ar to the power of 3 minus 1 end exponent space rightwards double arrow space ar to the power of 4 minus 4 ar squared space equals space 0 space rightwards double arrow space ar squared left parenthesis straight r squared minus 4 right parenthesis space equals space 0

rightwards double arrow                 straight r squared space minus space 4 space equals 0                                                             (∵ <pre>uncaught exception: <b>mkdir(): Permission denied (errno: 2) in /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/util/sys/Store.class.php at line #56mkdir(): Permission denied</b><br /><br />in file: /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/util/sys/Store.class.php line 56<br />#0 [internal function]: _hx_error_handler(2, 'mkdir(): Permis...', '/home/config_ad...', 56, Array)
#1 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/util/sys/Store.class.php(56): mkdir('/home/config_ad...', 493)
#2 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/FolderTreeStorageAndCache.class.php(110): com_wiris_util_sys_Store->mkdirs()
#3 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/RenderImpl.class.php(231): com_wiris_plugin_impl_FolderTreeStorageAndCache->codeDigest('mml=<math xmlns...')
#4 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/TextServiceImpl.class.php(59): com_wiris_plugin_impl_RenderImpl->computeDigest(NULL, Array)
#5 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/service.php(19): com_wiris_plugin_impl_TextServiceImpl->service('mathml2accessib...', Array)
#6 {main}</pre>)

rightwards double arrow                         straight r equals plus-or-minus 2.

Putting r = 2 in (i), we get a + 2a = -4 rightwards double arrow a = -4/3.

∴    G.P. is space space space fraction numerator negative 4 over denominator 3 end fraction comma space fraction numerator negative 4 over denominator 3 end fraction left parenthesis 2 right parenthesis. space fraction numerator negative 4 over denominator 3 end fraction left parenthesis 2 right parenthesis squared comma space.......... space or space fraction numerator negative 4 over denominator 3 end fraction comma space fraction numerator negative 8 over denominator 3 end fraction comma space fraction numerator negative 16 over denominator 3 end fraction comma space.........

Now, putting r = -2 in (i), we get a + a(-2) = -4 rightwards double arrow -a = -4 or a = 4.

∴  G.P. is 4, 4(-2), 4(-2)2,   .... or 4, -8, 16, ...........

146 Views

Advertisement
Advertisement
115. If A.M. and G.M. of roots of a quadratic equation are 8 and 5 respectively, then obtain the quadratic equation.
153 Views

 Multiple Choice QuestionsLong Answer Type

116. If a and b are roots of x2 – 3x+p = 0 and c, d are roots of x2 – 12x + q = 0 where a, b, c, d form a GP., prove that (q + p) : (q – p) = 17 : 15
265 Views

117. Find four numbers in GP. whose sum is 85 and product is 4096.
477 Views

 Multiple Choice QuestionsShort Answer Type

118. Find the sum of n terms of the series whose nth term is given by 

straight n squared plus 2 to the power of straight n
136 Views

Advertisement

 Multiple Choice QuestionsLong Answer Type

119.

Insert 5 G.M.'s between 32 over 9 space and space 81 over 2

138 Views

 Multiple Choice QuestionsShort Answer Type

120.

Find the sum of first n natural numbers  Or

Evaluate sum straight n space or space sum from straight k equals 1 to straight n of space straight k

127 Views

Advertisement