Some problems require the reverse of the process we just used. The
sum-to-product formulas allow us to express sums of sine or cosine as products. These formulas can be derived from the product-to-sum identities. For example, with a few substitutions, we can derive the sum-to-product identity for
sine . Let
and
Then,
Thus, replacing
and
in the product-to-sum formula with the substitute expressions, we have
The other sum-to-product identities are derived similarly.
Sum-to-product formulas
The
sum-to-product formulas are as follows:
Writing the difference of sines as a product
Write the following difference of sines expression as a product:
We begin by writing the formula for the difference of sines.
Substitute the values into the formula, and simplify.
if three forces F1.f2 .f3 act at a point on a Cartesian plane in the daigram .....so if the question says write down the x and y components ..... I really don't understand
a fixed gas of a mass is held at standard pressure temperature of 15 degrees Celsius .Calculate the temperature of the gas in Celsius if the pressure is changed to 2×10 to the power 4