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Trigonometry: Calculate sin 75degrees. Use the fact that: cos (u + v) = cosucosv - sin u sinv
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cos 75=cos(45+30)=cos45cos30-sin45sin30 =1/root(2)*root(3)/2-1/root(2) *1/2 =root(3)-1/root(2)
do you mean cos 75?
sai1234 has it
Sin 75 could be written as sin ( 30+45) Sin(A+B) = sinA cosB + cos A sinB SinB (30 + 45) = sin 30 cos 45 + cos 30 sin 45{ sin 30 = 1/2, cos 30 = sqrt( 3)/2, sin45= cos 45=1/sqrt (2)} Putting the values 1/2x 1/ sqrt (2) + sqrt(3)/2 x 1/ sqrt(2) 1/2sqrt(2) + sqrt(3) / 2sqrt(2). Taking LCM [1+ sqrt(3)]/2sqrt(2)
sin(750=root(1-cos752) root(1-(root(3)-1/root(2))^2) =0.96
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thanks @sai1234 !!
and @nishika17
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