Question

Can u pls help me solve this. I will send u the other options

Answer 1

Given:

`cos300^(\degree)`

Required:

We need to determine the exact value of the given expression.

Step-by-step explanation:

`We\text{ know that }cos2\theta=2cos^2\theta-1.`
`Substitute\text{ }\theta=150\degree\text{ in the equation.}`

`cos(2*150)=2cos^2(150\degree)-1.`

`cos(300\degree)=2cos^2(150\degree)-1.`
`\text{We know that }cos2\theta=1-2sin^2\theta.`

`Substitute\text{ }\theta=150\degree\text{ in the equation.}`

`cos(2*150)\degree=1-2sin^2(150)\degree.`

`cos(300)\degree=1-2sin^2(150)\degree.`

Final answer:

`cos(300\degree)=2cos^2(150\degree)-1.`

`cos(300)\degree=1-2sin^2(150)\degree.`