(sint+cost)/(cost-sint)怎么算的,等于tan(t+π/4)

网友回答

(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)
======以下答案可供参考======
供参考答案1:
(sint+cost)/(cost-sint)分子分母同时除以cost
=(sint/cost+cost/cost)/(cost/cost-sint/cost)
=(tant+1)/(1-tant)
=(tant+tanπ/4)/(1-tanttanπ/4)
=tan(t+π/4)
供参考答案2:
三角函数?只有计算器能算。。。