we know that cos(a - b) = cos(a) cos(b) + sin(a) sin(b)
given a = π/3 and b = π/5
cos(π/3) cos(π/5) + sin(π/3) sin(π/5) = cos((π/3) - (π/5) = cos(2π/15)
hope it helps

5 0

3 years ago

A ball is thrown in the air from a ledge. Its height in feet is represented by f16(2-5x - 6), where x is the number of seconds s

Assoli18 [71]

Height in feet is represented by $f(x) = -16(x^2-5x-6)$

The height of the ball is 0 feet when it hits the ground.

So we replace height f(x) by 0 and solve for x to find the time taken to reach the ground

$f(x) = -16(x^2-5x-6)$

$0= -16(x^2-5x-6)$ ( divide by -16 on both sides)

$0=(x^2-5x-6)$

Now factor it

(x-6)(x+1) =0

x-6 =0 and x+1=0

x=6 and x=-1

Time cannot be negative so we ignore -1

x = 6 seconds

It will take 6 seconds for the ball to reach the ground.

6 0

4 years ago

A computer store bought a program at a cost of ​$20 and sold it at a selling price of ​$25. Find the percent markup.

A computer store bought a program at a cost of $20 and sold it at a selling price of $25. Find the percent markup.