Answer:
1) ∫ x² e^(x) dx
4) ∫ x cos(x) dx
Explanation:
To solve this problem, eliminate the choices that can be solved by substitution.
In the second problem, we can say u = x², and du = 2x dx.
∫ x cos(x²) dx = ∫ ½ cos(u) du
In the third problem, we can say u = x², and du = 2x dx.
∫ x e^(x²) dx = ∫ ½ e^(u) du