The berries will be $3, because she is buying one lb of them at $3/lb
Right side of the equation:
cos ( A - B ) - cos ( A + B ) =
= cos A cos B + sin A sin B - ( cos A cos B - sin A sin B ) =
= cos A cos B + sin A sin B - cos A cos B + sin A sin B =
= 2 sin A sin B - left side of the equation ( correct )
Answer:
mdf= 90 degrees
Step-by-step explanation:
