Q14 of 30 Page 5

If then prove that Hence, show that

Given: x cos(a + y) = cos y


To prove:


x cos(a + y) = cos y



Differentiating both sides with respect to x:









{∵ sin (A + B) = sin A cos B – cos A sin B}




Hence Proved



Differentiating again both sides:












{∵ sin 2x = 2 sin x cos x}



Hence Proved


More from this chapter

All 30 →
12

Differentiate (x.cos x)x + (x.sin x)1/x with respect to x.

 13

If x = a(θ - sin θ) and y = a(1 + cos θ). Find at .

 15

If and find the values of at and

16

Find the values of a and b such that the function defined by

is a continuous function.