Verified answer

y=cos(sin√ax+b)

let

√ax+b = u

du/dx = a/2(√ax+b)...............(1)

du= a/2(√ax+b)dx

now function becomes cos(sin u)

now

let sin u = p

dp/du = cos u..........(2)

dp= cos u du

dp= cos u(a/2(√ax+b))dx

now function becomes cos p

dy/dp = -sin p...............(3)

dy= -sin p dp

dy = -sin p (cos u(a/2(√ax+b)))dx

dy/dx = -sin p (cos u(a/2(√ax+b)))

= -sin (sin (√ax+b)cos (√ax+b)(a/2(√ax+b)...................by putting the value of p and u

i hope u understand

cheers!!