Question

x=acos4teta y=asin4teta elemimating teta​

Answer 1

Answer:

$\Huge\sf\red{Answer}$

Given, x=acos 4 θ and y=asin 4θ

On differentiating with respect to θ respectively, we getdθdx

=4acos 3 θ(−sinθ)

=−4asinθcos 3 θand dθdy

=4asin 3θcosθ

∴ ddxd = dθdxdθdy

= −4asinθcos 3θ4asin 3 θcosθ

⇒ ddxd =− cos 2θsin 2θ =−tan 2 θ

Now, ( dxdd ) θ= 43π =−tan 2 ( 43π )=−1