Please wait...
/
-
If the coefficients of rth, (r+ 1)th and (r + 2)th terms in the binomial expansion of (1 + y)m are in A.P., then m and r satisfy the equation
Let P be the point (1, 0) and Q a point on the locus y2 = 8x. The locus of mid-point of PQ is
P = (1, 0) Q = (h, k) such that k2 = 8h Let (α, β) be the midpoint of PQ
The equation of the tangent to the curve that is parallel to the x-axis is
Since the tangent is parallel to x axis, the slope of the tangent is 0, or y' =0. Also, equation of the tangent will be of the form, y=k. Let's find the value of x first.
If ω (≠ 1) is a cube root of unity, and (1 + ω)7 = A + Bω. Then (A, B) equals:
(1 + ω)7 = A + Bω We know that 1 + w + w2 = 0 => (-ω2)7 = A + Bω => -w14 = A + Bω => - ω12 x ω2 = A + Bω w12 = 1 => -ω2 = A + Bω 1 + ω = A + Bω ⇒ A = 1, B = 1. Hence, option B is correct.
Area of the greatest rectangle that can be inscribed in the ellipse
Area of rectangle ABCD = (2acosθ) (2bsinθ) = 2absin2θ ⇒ Area of greatest rectangle is equal to 2ab, when sin2θ = 1.
Hence, option A is correct.
The shortest distance between the line y – x = 1 and the curve x = y2 is
A bird is sitting on the top of a vertical pole which is 20 m in height and its elevation from a point O on the ground is 45°. It flies off horizontally straight away from the point O. After one second, the elevation of the bird from point O is reduced to 30°. Calculate the speed (in m/s) of the bird.
\
Correct (-)
Wrong (-)
Skipped (-)