Question

Tan square theta upon sec square theta equal to sin theta

Answer 1

tan2 theta = sin2theta / cos2 theta

sec2theta = 1/ cos2 theta

so.
sin2theta upon cos2theta / 1upon cos2theta

cos2theta would cancel with cos2theta

so...remaining is sin theta

Answer 2

tan2(θ)/sec2(θ) can be rewritten as

(sin2(θ)/cos2(θ))/(1/cos2(θ))

Which can be simplified to (sin2(θ)*cos2(θ))/cos2(θ)

Cancelling out the cos2(θ)

Means it is equal to sin2(θ)... not sin(θ)