Find the expression that is equal to (tan(theta)+cot(theta))^2:

Question

a)  tan^2(theta)+cos^2(theta)

 

b)  2tan(theta)cot(theta)

 

c)  2cot^2(theta)-1

 

d)  sec^2(theta)+csc^2(theta)

Answer 1

squaring the given expression gives you tan²θ + 2 + cot²θ = (1 +  tan²θ) + (1 + cot²θ)

and now use two of the versions of the Pythagorean identity: = sec²θ + csc²θ

Answer: D