3 years ago

Prove the following identity. [sin(x+y)+sin(x-y)]/[cos(x+y)+cos(x-y)] = tan(x)

1 answer:

4 0

$\frac{sin(x + y) + sin(x - y)}{cos(x + y) + cos(x - y)} = tan(x)$
$\frac{(sin(x)cos(y) + cos(x)sin(y)) + (sin(x)cos(y) - cos(x)sin(y))}{(cos(x)cos(y) - sin(x)sin(y)) + (cos(x)cos(y) + sin(x)sin(y))} = tan(x)$
$\frac{(sin(x)cos(y) + sin(x)cos(y)) + (cos(x)sin(y) - cos(x)sin(y))}{(cos(x)cos(y) + cos(x)cos(y)) + (-sin(x)sin(y) + (sin(x)sin(y))} = tan(x)$
$\frac{2sin(x)cos(y)}{2cos(x)cos(y)} = tan(x)$
$\frac{sin(x)}{cos(x)} = tan(x)$

You might be interested in

Choose the correct answer.

makkiz [27]

Answer is option c which is 2 days

3 0

2 years ago

Read 2 more answers

A recipe needs 2 tablespoons of vegetable oil for every 34 cup of flour. If you plan to use 3 cups of flour, how much vegetable

Olenka [21]

If 34 cups=2 tablespoons of oil
3 cups=3/34 *2
Then u solve from there. I hope this helps.

4 0

3 years ago