Answer:
Below in bold.
Step-by-step explanation:
(a) y=x^2sin2x
Using the Product Rule:
dy/dx = x^2*2cos2x + 2xsin2x
dy/dx = 2x(xcos2x + sin2x).
(b) y=ln sqrt(1+t^2)
y = ln (1 + t^2)^1/2
Using the chain rule:
dy/dx = 1 / (1 + t^2)^1/2 * 1/2(1 + t^2)^-1/2 * 2t
= 2t/(1 + t^2)^1/2 * 1/ (2(1 + t^2)^1/2
= 2t / 2(1 + t^2)
= t / ( 1 + t^2).
