Show so that the expression of cos4A in term of SinA is 8Sin^4 - 8Sin^2A + 1 plz solve anyone.. I really need this answer

Step-by-step explanation:

L

H

S

=

cos

4

x

=

2

cos

2

(

2

x

)

−

1

=

2

(

cos

(

2

x

)

)

2

−

1

=

2

(

2

cos

2

x

−

1

)

2

−

1

=

2

(

4

cos

4

x

−

4

cos

2

x

+

1

)

−

1

=

8

cos

4

x

−

8

cos

2

x

+

2

−

1

=

8

cos

4

x

−

8

cos

2

x

+

1

=

R

H

S

Again

L

H

S

=

cos

4

x

=

2

cos

2

(

2

x

)

−

1

=

2

(

1

−

2

sin

2

x

)

)

2

−

1

=

2

(

1

−

4

sin

2

x

+

4

sin

4

x

)

−

1

=

2

−

8

sin

2

x

+

8

sin

4

x

−

1

=

8

sin

4

x

−

8

sin

2

x

+

1

=

R

H

S

sin

2

x

+

cos

2

x

=

1

cos

2

x

=

1

−

sin

2

x

substitute in the equation as follows

8

cos

4

x

−

8

cos

2

x

+

1

=

8

cos

2

x

(

cos

2

x

−

1

)

+

1

=

8

(

1

−

sin

2

x

)

(

1

−

sin

2

x

−

1

)

+

1

=

8

(

1

−

sin

2

x

)

(

−

sin

2

x

)

+

1

=

8

sin

4

x

−

8

sin

2

x

+

1

answer: h

step-by-step explanation:

region b will make the inequalities y < 2x + 1 and y > -x - 2 true ⇒ answer a

step-by-step explanation:

* lets study the graph and the inequality to solve the question

- the inequality y > -x - 2

∵ the form of the inequality is y > mx + c , m is the slope of the line

  and c is the y-intercept (the line intersect y-axis at point (0 , c)

∴ c = -2 that means the line intersect the y-axis at point (0 , -2)

∵ the sign of the inequality is >

∴ we shad the part over the line

  region a and b

- the inequality y < 2x + 1

∵ the form of the inequality is y > mx + c , m is the slope of the line

  and c is the y-intercept (the line intersect y-axis at point (0 , c)

∴ c = 1 that means the line intersect the y-axis at point (0 , 1)

∵ the sign of the inequality is <

∴ we shad the part under the line

  region b and c

∵ the common region between the two lines is region b

∴ region b will make the inequalities y < 2x + 1 and y > -x - 2 true