prove (1-cos(x))(1+sec(x))=-sin(x)

الحلّ

prove

(1 - cos (x)) (1 + sec (x)) = - sin (x)

خطأ

خطوات الحلّ

(1 - cos (x)) (1 + sec (x)) = - sin (x)

لا يتساوى الطرفان

\Rightarrow خطأ

4 cot (x) = cot (x) sin^{2} (x)

\frac{1}{1 + tan ^{2} ( x )} = sin^{2} (- cos^{2} (x))

cos^{2} (7 x) - sin^{2} (7 x) = cos (14 x)

tan^{2} (θ) csc^{2} (θ) = 1 + tan^{2} (θ)

cos (4 a) = 8 cos^{4} (a) - 8 cos^{2} (a) + 1