Guo Xiang's answer to Zoe's Secondary 4 A Maths question.
may i know how you got from the third to the fourth step?
Factorise out 1/cos x from 1/cos x - cos x to get (1/cos x)(1 - cos^2 x)
Since there was no cos in the answer, i thought that cos^2 x should have to appear somewhere so that it could be converted to sin :)
ohhhhhhhh okay understand! thank you so much!
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