Question

Equation of the normal to the curve y = sinx at the origin is ???

Answer 1

Answer :

The curve is

y = sinx ...(i)

Now, differentiating both sides of (i) with respect to x, we get

dy/dx = cosx

⇒ dx/dy = secx

⇒ - dx/dy = - secx

So, (- dx/dy) at the point (0, 0) is

= - sec0

= - 1

∴ at the origin (0, 0), the required normal be

y - 0 = - 1 (x - 0)

⇒ y = - x

⇒ x + y = 0

Hope it helps! (: