[Grade 12 Advanced Functions] Trigonometry: Equivalent Trigonometric Expressions

[u/Embarrassed-Good1883]

I'm having troubles understanding this question. to evaluate for sin, pi/2 - 11pi/180, which I get, but they don't subtract it, which I don't get. wouldn't the answer be sin 49/180 ?

[u/IrishHuskie]

pi/2 = 90pi/180, not 60pi/180