tan(x+20)=1,x=?

tan(x+20)=1,x=? 1+(tan x)=? 求证tan(x+y)*tan(x-y)=tan^2x-tan^2y/1-tan^2xtan^2y tan（ x/2+π/4）+tan（x/2-π/4 ）=2tanxtan(x/2+π/4)+tan(x/2-π/4)=[tan(x/2)+tan(π/4)]/[1-tan(x/2)tan(π/4)]+[tan(x/2)-tan(π/4)]/[1+tan(x/2)tan(π/4)]=[tan(x/2)+1]/[1-tan(x/2)]+[tan(x/2)-1]/[1+tan(x/2)]=[(tan(x/2)+1)^2-(tan(x/2)-1)^2]/[1-(tan(x tan(x+45)-tan(45-x)=? (tan x)-1=什么? 判断函数y=(tan(x)*tan(x)-tan(x))/(1-tan(x))的奇偶性请写出过程,谢谢! 求证tan(x-y)+tan(y-z)+tan(z-x)=tan(x-y)tan(y-a)tan(z-x) 这道题为什么第二步的+到了第三步变成了-1.tan(x/2+π/4)+tan(x/2-π/4)=[tan(x/2)+tan(π/4)]/[1-tan(x/2)tan(π/4)]+[tan(x/2)-tan(π/4)]/[1+tan(x/2)tan(π/4)]=[tan(x/2)+1]/[1-tan(x/2)]+[tan(x/2)-1]/[1+tan(x/2)]=[(tan(x/2)+1)^2-(tan(x/2)- tan(x+y)= (sin x) + (cos x) = (tan x) + 1/(tan x)0 f(x)=tan+1/tan 奇函数还是偶函数 求证：tan x/2=sin x/(1+cos x) 求证：1-sin(x)=cos(x)*tan(x/2) lim(x→0)tan(x)ln(1+x)=? 函数f(x)=tan(x+1)+tan(x+2)+tan(x+3)+.+tan(x+2013)图像的一个对称中心为? 证明:tan(x+y)tan(x-y)=tan②x-tan②y/1-tan②xtan②y②表示平方 1/cos(x) - tan(x) = 3 求sin(x)1/cos(x) - tan(x) = 3求sin(x)