There are two problems in senior high school mathematics, which are twice as big. I'm so worried! ! ! ! ! ! ! ! !

1. Original formula =(2cos? 10)÷(2 * 2 sin 10 cos 10)-sin 10 *( 1-tan？ 5)÷tan5)

Reduce (part of)

= 1/(2 tan 10)-2 sin 10/tan 10

( 1-tan？ 5)÷tan5 = 2/tan 10 because 2tan5÷( 1-tan? 5)=tan 10, he refers to the formula of double angle from the bottom.

= (1-4 sin10)/2 tan10 The answer is strange and wrong. Don't blame me.

2. Original formula = sinx * (1+cosy)+cosxsiny-sinx.

simplify

=sinXcosY+cosXsinY

=sin(X+Y)

When x=π

Original formula =sin(π+Y)= -sinY

y=π/2

Symmetry axis kπ+π/2

Center of symmetry (kπ, 0)

I'm exhausted. Please forgive me if I am wrong. I'm doing it now. Freshman just went through the college entrance examination. It seems that your formula is not ripe. Two questions are simple.

Come on, math.