Question

sin 7π\2 . cos π\4 - cos 7π\2 . sin π\4 = ?
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Answer 1

Answer:

ANSWER-

-1/2^1/2 or -1/ROOT2

Step-by-step explanation:

(pie)=180 degrees BTW

7(pie)/4 = 7*180/2 = 630 degree

(pie)/4 = 180/4 = 45 degree

sin(a-b) = sina.cosb - cosa.sinb

here, sin630.cos45 -cos630.sin45

that gives, sine(630-45)

sine585 degrees

sin(360+225)

which gives sin215 degrees

sin(180+45)

= -sin45 degrees

= -1/root2   or  = -1/2^1/2

HOPE IT HELPS:)