Application of DerivativeHard
Question
At what point the tangent line to the curve y = cos(x + y), (-2π ≤ x ≤ 2π) is parallel to x + 2y = 0
Options
A.(π/2, 0)
B.(-π/2 , 0)
C.(3π/2, 0)
D.(-3π/2, π/2)
Solution
y = cos(x + y) (-2π ≤ x ≤ 2π)
= -sin(x + y) 
(1 + sin(x + y) = -sin(x + y)

parallel to x + 2y = 0

2 sin (x + y) = 1 + sin (x + y)
sin (x + y) = 1
so x =
, y = 0

parallel to x + 2y = 0
2 sin (x + y) = 1 + sin (x + y)
sin (x + y) = 1
so x =
Create a free account to view solution
View Solution FreeMore Application of Derivative Questions
If equation of normal at a point (m2, -m3) on the curve x3 - y2 = 0 is y = 3mx - 4m3, then m2 equals-...The length of subtangent at any point of the curve y = bex/a is-...The length of the subtangent at any point of the curve xmyn = am+n is proportional to-...The abscissa of the point on the curve √xy = a + x, the tangent at which cuts off equal intercepts from the co-ord...The equation of the normal to the curve y2 = 4ax at point (a, 2a) is-...