(Drag and drop the missing words) Question 3 In the integral Not yet answered dz Marked out of 7 Va? P Flag question we may use x= and dx= substitutions to reduce the integral to de. This step requires that a>0 and >0. Similarly, in the integral da a2 + 22 we may use x= Integrals like da can also be evaluated by rather than trigonometric substitutions. However, the integral | V - dz cannot. In this case, an appropriate substitution is x= and dx= a cose de a sine improper integral law of cosines ratio test cos e a sec e a tane a sece tane de root test partial fractions