71.Find the discriminant of the following quadratic equations, and hence find the nature of its roots.
–x2 + 2x + 3 = 0 Here, a = 1, b = 2, c = 3 Now, D = b2 – 4ac = (2)2 –4(–1)(3) = 4 + 12 = 16 Since, D > 0 Therefore, given quadratic equation has real roots.
109 Views
Advertisement
72.Find the discriminant of the following quadratic equations, and hence find the nature of its roots.
92 Views
73.For what value of A, are the roots of the quadratic equation 3x2 + 2kx + 27 = 0 real and equal?
547 Views
74.For what value of A, are the roots of the quadratic equation: kx2 + 4x + 1 = 0 equal and real?
224 Views
Advertisement
Long Answer Type
75.For what value of A, does (k – 12)x2 + 2 (k – 12)x + 2 = 0 have equal roots?
375 Views
Short Answer Type
76.For what value of A, does the equation 9x2 + 3kx + 4 = 0 have equal roots?
626 Views
Long Answer Type
77.If (–5) is a root of the quadratic equation 2x2 + px – 15 = 0 and the quadratic equation p(x2 + x) + k = 0 has equal roots, then find the values of p and A.
117 Views
78.If one of the roots of the quadratic 2x2 + px – 4 = 0 is 4. Write value of p.
164 Views
Advertisement
Short Answer Type
79.Find the discriminant of the quadratic equation.
125 Views
80.Show that x = – 3 is a solution of x2 + 6x + 9 = 0.