SA 3

∫ 6 x (x² +1 )² dx

• ( x² + 1)³ + C
• 3 ( x² + 1)³ + C
• ( x² + 1)¹ + C
• 6 ( x² + 1)³ + C

∫ 2x cos(x²) dx

• sin(x²) + C

• 2 sin ( 2x ) + C

• (1/2) sin(x²) + C

• 4 cos(2x ) + C

• ln(2x²+6) + C
• ln(2x²+6)(4x) + C
• 1/(2x²+6) + C
• 1/(2x²+6)² + C

What is the choice of u for ∫ e^x(1+e^x)^(1/2) dx?

• e^x

• 1+e^x

• (1+e^x)^(1/2)

• (e^x)^(1/2)

• None of these

Use substitution to evaluate the integral $\int4\sec^24x\ \sqrt{\tan4x}\ dx$