Find the equations of all lines having slope -1 that are tangent

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 Multiple Choice QuestionsShort Answer Type

101. Find the point on the curve y = x3 – 11 x + 5 at which the tangent has the equation y = x – 11.
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102.

Find the point on the curve y = x3 – 2x2 – 2x at which the tangent lines are parallel to the line y = 2x – 3.

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103.

Find the points on the curve y = x3 – 2x2 – x at which the tangent lines are parallel to the line y = 3x – 2.

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104.

Find the equation of the tangent to the curve x2 + 3y = 3, which is parallel to the line y – 4x + 5 = 0. 

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105.

Find the equations of all lines having slope -1 that are tangents to the curve straight y equals fraction numerator 1 over denominator straight x minus 1 end fraction. straight x not equal to 1.


The equations of the curve is straight y equals space fraction numerator 1 over denominator straight x minus 1 end fraction space equals left parenthesis straight x minus 1 right parenthesis to the power of negative 1 end exponent
therefore space space space space space space dy over dx space equals space left parenthesis negative 1 right parenthesis thin space left parenthesis straight x minus 1 right parenthesis to the power of negative 2 end exponent space equals space minus fraction numerator 1 over denominator left parenthesis straight x minus 1 right parenthesis squared end fraction
therefore space space space space space space slope space of space tangent space equals space minus fraction numerator 1 over denominator left parenthesis straight x minus 1 right parenthesis squared end fraction
But space slope space of space tangent space space equals space minus 1 space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space left parenthesis given right parenthesis
therefore space space space space space space minus fraction numerator 1 over denominator left parenthesis straight x minus 1 right parenthesis squared end fraction space equals space minus 1 space space space space rightwards double arrow space space space space space fraction numerator 1 over denominator left parenthesis straight x minus 1 right parenthesis squared end fraction space equals space 1 space space space space rightwards double arrow space space space space left parenthesis straight x minus 1 right parenthesis squared space equals space 1
rightwards double arrow space space space space space space straight x minus 1 space equals space plus-or-minus 1 space space space space space space space space space space space space space space space space space space space space space space rightwards double arrow space space space space straight x space equals space 0 comma space space 2
When space straight x space equals space 0 comma space space space space space straight y space equals space fraction numerator 1 over denominator 0 minus 1 end fraction space equals space minus 1
When space straight x space equals space 2 comma space space space space straight y space equals space fraction numerator 1 over denominator 2 minus 1 end fraction space equals space 1 over 1 space equals space 1

∴   there are two tangents to the given curve with slope – 1 and passing through the points (0, – 1) and (2, 1).
The equation of tangent through (0, – 1) is
y – (– 1) = – 1 (x – 0) or y + 1 = – x  or  x + y + 1 = 0
The equation of tangent through (2, 1) is
y – 1 = – 1 (x – 2) or y – 1 = – x + 2 or x + y – 3 = 0

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106.

Find the equation of all lines having slope 2 and being tangent to the curve straight y plus fraction numerator 2 over denominator straight x minus 3 end fraction space equals space 0.

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 Multiple Choice QuestionsLong Answer Type

107.

Find the equation of all lines having 0 slope and that are tangent to the curve straight y equals fraction numerator 1 over denominator straight x squared minus 2 straight x plus 2 end fraction.

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 Multiple Choice QuestionsShort Answer Type

108.

Find the equation of the tangent to the curve straight y equals square root of 3 straight x minus 2 end root which is parallel to the line 4x - 2y + 5 = 0

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 Multiple Choice QuestionsLong Answer Type

109.

Find the equation of tangents to the curve
y = cos (x + y), – 2 straight pi ≤ x ≤ 2 straight pi
that are parallel to the line x + 2y = 0.

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110.

Find the point on curve 4x2 + 9y2 = 1, where the tangents are perpendicular to the line 2y + x = 0.

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