If f(x) = -2 cos x, findf(-300 º). Do not use a calculator.

- 1

Step-by-step explanation:

Using the trigonometric identity

cos(- x) = cosx and exact value cos60° =

Given

f(x) = - 2cosx , then

f(- 300° )

= - 2cos(- 300)°

= - 2cos(300)°

= - 2cos(360 - 300)°

= - 2cos60°

= - 2 ×

= - 1

answer: c.  

step-by-step explanation:

mixtures containing substances that get attracted to magnet can be separated using a magnet. we can separate iron from a mixture of sand and iron, as only iron attracts to the magnet.