Question

find the value of :cos 240°.sin300°-sin330°cos300°. detail
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Answer 1

Step-by-step explanation:

cos240= cos( 90.2+60 )= -cos60 = -1/2

sin300= sin ( 3.90+30) = - cos30= -√3/2

sin330= sin (3.90+60) = - cos60= -1/2

cos300= cos ( 3.90+30)= - cos30= -√3/2

now

cos240.sin300-sin330.cos300=(-1/2).(-√3/2)-(-1/2).-(√3/2) = 0