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Trump
Trump

Secondary 4 chevron_right Malaysia

Urgent. Why the answer for this question is 0 and 360? I just got cos x=0 which is 90 and 270

Date Posted: 4 years ago
Views: 683

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Wai Mun
Wai Mun's answer
128 answers (A Helpful Person)
1st
Your workings is actually not wrong as u obtained cos x = 0 or cos x = 1.

But u have to reject cos x = 0. This is because sec x = 1/cos x and for
sec x and sec^2 x to be defined, cos x cannot be 0.

Hope this helps and I have provided an alternative approach to solving this using the trigonometric Pythagorean identities.