根号2/4sin(π/4-x)+根号6/4cos(π/4-x) 化简根号2/4就是四分之根号二
问题描述:
根号2/4sin(π/4-x)+根号6/4cos(π/4-x) 化简
根号2/4就是四分之根号二
答
原式=根号2/2【1/2sin(∏/4-x)根号3/2cos(∏/4-x)】
=根号2/2【sin(∏/4-x-∏/3)】
=根号2/2sin(-x-∏/12)
答
根号2(sinX-cosX) =2*(sinXcos45-cosXsin45) =2sin(X-45) 根号2/4sin(π/4-X)+根号6/4cos(π/4-X) =根号2/8*[sin(π/4-X)cos60+cos
答
√2/4 sin(π/4-x)+√6/4 cos(π/4-x)
=√2/2 [1/2 sin(π/4-x)+√3/2 cos(π/4-x)]
=√2/2 [cosπ/3 sin(π/4-x)+sinπ/3 cos(π/4-x)]
=√2/2 [ sin(π/4-x+π/3)]
=√2/2 [ sin(7π/12-x)]
=√2/2 [ sin(π/2+π/12-x)]
=√2/2 [ cos(π/12-x)]