展开 2cos(x)(cos(x)+1)

解答

展开

2 cos (x) (cos (x) + 1)

2 cos^{2} (x) + 2 cos (x)

求解步骤

2 cos (x) (cos (x) + 1)

使用分配律:

a (b + c) = ab + a c

2 cos (x) (cos (x) + 1) = 2 cos (x) cos (x) + 2 cos (x) \cdot 1

= 2 cos (x) cos (x) + 2 cos (x) \cdot 1

化简

2 cos (x) cos (x) + 2 cos (x) \cdot 1 : 2 cos^{2} (x) + 2 cos (x)

= 2 cos^{2} (x) + 2 cos (x)

s im pl i f y 4 (cos (x) - cos (2 x))

e x p an d (4 t - t^{2}, t - (1 - t)^{2}, 1 - t - 16 t^{2}) \cdot (4, 1, - 1)

e x p an d - \frac{4}{( 2 x + 1 ) ^{2}}

e x p an d lo g_{3} (25)

e x p an d lo g_{c} (8 \frac{x ^{2}}{y ^{3} c ^{8}})