Question: i) Show that the equation 2 sin x cos x = 1 can be written as a quadratic equation in cos x. ii) Solve

i) Show that the equation 2 sin² x − cos x = 1 can be written as a quadratic equation in cos x.

ii) Solve the equation 2 sin² x − cos x = 1 for 0° ≤ x ≤ 180°.

iii) Hence solve the equation

2 sin 20 cos X 2 = 1


for 0° ≤ x ≤ 180°.

2 sin 20 cos X 2 = 1

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i Using the identity sin x cos x 1 we can rearrange the given equation as 21 cos x cos x 1 Expanding ... View full answer

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