Question

25 points for correct answers
Anything except correct answers will be reported

Answer 1

Let sinx = n
Then,⇒ 2n² - 3n -1
By Quadratic formula 
⇒ -b+√b²-4ac/2a  , -b-√b²-4ac/2a
⇒ -(-3) + √(-3)²-4(2)(-1)  ,   -(-3) - √(-3)²-4(2)(-1) 
⇒ 3 + √9+8   ,   3 - √9+8
⇒ 3 + √17   ,  3 - √17

Then sin x = 3+√17  ,  3-√17and we cannot find the value of x for the above query.

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But when the ques is 2sin²x - 3sinx +1

Let sinx = n
Then,⇒ 2n² - 3n +1
By Quadratic formula 
⇒ -b+√b²-4ac/2a  , -b-√b²-4ac/2a
⇒ -(-3) + √(-3)²-4(2)(1)  ,   -(-3) - √(-3)²-4(2)(1) 
⇒ 3 + √9-8/2   ,   3 - √9-8/2
⇒ 3 + √1/2   ,  3 - √1/2
⇒ 4/2  , 2/2
⇒ 2 , 1
Neglecting 2
Then sin x = 1 Then sin x = sin 90°
               x = 90°

:) Hope this helps !!!!

Answer 2

Answer:

the answer is very useful

Step-by-step explanation: