Question

Rút gọn biểu thức sau:\(A=\left[tan\frac{17\pi}{4}+tan\left(\frac{7\pi}{2}-x\right)\right]^2+\left[cot\frac{17\pi}{4}+cot\left(7\pi\right)-x\right]^2\)

Answer 1

\(\cot\left(7\pi\right)\) ko xác định bạn ơi

Answer 2

Thì tách bình thường thôi :)

\(A=\left[\tan\left(4\pi+\frac{\pi}{4}\right)+\tan\left(3\pi+\frac{\pi}{2}-x\right)\right]^2+\left[\cot\left(4\pi+\frac{\pi}{4}\right)+\cot\left(-x\right)\right]^2\)

\(A=\left[\tan\left(\frac{\pi}{4}\right)+\cot x\right]^2+\left[\cot\left(\frac{\pi}{4}\right)-\cot x\right]^2\)

\(A=\left(1+\cot x\right)^2+\left(1-\cot x\right)^2=...\)