Trigonometric Substitution...3

Section 5.1





How is 73 done?

 

72. correct

73.
use the reciprocal functions and other identities like
csc(theta) =1/sin(theta)
sec(theta) =1/cos(theta), then express cos(theta) in terms of sin(theta) ; cos(theta) =sqrt(1-sin^2(theta))

and, do the other one in similar way

 

Thank you.