设α为锐角,若cos(α+π/6)=3/5,则sin(α-π/12)=

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设α为锐角,若cos(α+π/6)=3/5,则sin(α-π/12)=设α为锐角,若cos(α+π/6)=3/5,则sin(α-π/12)=设α为锐角,若cos(α+π/6)=3/5,则sin(α-π

设α为锐角,若cos(α+π/6)=3/5,则sin(α-π/12)=
设α为锐角,若cos(α+π/6)=3/5,则sin(α-π/12)=

设α为锐角,若cos(α+π/6)=3/5,则sin(α-π/12)=
cos(a+π/6)=3/5
sin(a+π/6)=4/5
sin(a-π/12)=sin[(a+π/6)-π/4]=sin(a+π/6)*cos(π/4)-cos(a+π/6)*sin(π/4)
=(4/5)*(√2/2)-(3/5)*(√2/2) =√2/10

罪(2A +π/12)= SIN(2A +π/ 3,π/ 4)
订购+π/ 6 = X
所以简化成罪(2X-π/ 4)=sin2xcosπ / 4-cos2xsinπ/ 4 =2sinxcosxcosπ/4-(2cosxcosx-1)sinπ/ 4
入已知条件cosx = 0/5的sinx = 4/5
获得未知的公式= 2 * 0.8 * 0.6 *cosπ/4-7/25sinπ/4= 17/25 *(1/2)^ 1/2