Here is the answer.
You just have to remember the given formula.
Option C:
x = 90°
Solution:
Given equation:

<u>To find the degree:</u>

Subtract 1 + cos²x from both sides.

Using the trigonometric identity:




Let sin x = u

Factor the quadratic equation.

u + 2 = 0, u – 1 = 0
u = –2, u = 1
That is sin x = –2, sin x = 1
sin x can't be smaller than –1 for real solutions. So ignore sin x = –2.
sin x = 1
The value of sin is 1 for 90°.
x = 90°.
Option C is the correct answer.
The first step to finding the developed form is to multiply each term in the parenthesis by 2
2 × 3x - 2 × 10
now,, youll need to calculate the product of the first multiplication set
6x - 2 × 10
finally,, multiply the last set of numbers
6x - 20
this means that the correct answer to your question is 6x - 20.
let me know if you have any further questions
:)
Answer:
Step-by-step explanation: