(sint+cost)/(cost-sint)怎么算的,等于tan(t+π/4)
题目
(sint+cost)/(cost-sint)怎么算的,等于tan(t+π/4)
答案
(sint + cost) / (cost-sint)
= [(sint + cost)/√2] / [(cost - sint)/√2]
= (sint cosπ/4 + cost sinπ/4) / (cost cosπ/4 - sint sinπ/4)
= sin(t+π/4) / cos(t+π/4)
= tan(t+π/4)
举一反三
已知函数f（x）=x，g（x）=alnx，a∈R．若曲线y=f（x）与曲线y=g（x）相交，且在交点处有相同的切线，求a的值和该切线方程．
我想写一篇关于奥巴马的演讲的文章,写哪一篇好呢?为什么好
最新试题
热门考点