Question

решите пожалуйста этот пример​

Answer 1

Ответ:

$4 \sin( \alpha ) + 10\cos {}^{2} ( \alpha ) = 7 \\ 4(1 -\cos {}^{2} ( \alpha ) ) + 10\cos {}^{2} ( \alpha ) = 7 \\ 4 - 4 \cos {}^{2} ( \alpha ) + 10 \cos{?}^{2} ( \alpha ) = 7 \\ 6 \cos {}^{2} ( \alpha ) = 3 \\ \cos {}^{2} ( \alpha ) = \frac{1}{2} \\ \\ 1 + {\tg}^{2} \alpha = \frac{1}{ \cos {}^{2} ( \alpha ) } \\ {\tg}^{2} \alpha = \frac{1}{ \cos {}^{2} ( \alpha ) } - 1 = \\ = \frac{1}{ \frac{1}{2} } - 1 = 2 - 1 = 1 \\ \\ {\tg}^{2} \alpha = 1$

Answer 2

Ответ:

4sin(α)+10cos

2

(α)=7

4(1−cos

2

(α))+10cos

2

(α)=7

4−4cos

2

(α)+10cos?

2

(α)=7

6cos

2

(α)=3

cos

2

(α)=

2

1

1+tg

2

α=

cos

2

(α)

1

tg

2

α=

cos

2

(α)

1

−1=

=

2

1

1

−1=2−1=1

tg

2

α=1