Which of the following represents the most accurate estimation of 664-127

MATH HELP PLZ!!!

RoseWind [281]

Answer:

a) $tan (157.5) = \frac{1-cos 315}{sin315}$

b)

$sin (165) =\sqrt{ \frac{1-cos (330) }{2}}$

c)

$sin^{2} (157.5) = \frac{1-cos (315) }{2}$

d)

cos 330° = 1- 2 sin² (165°)

Step-by-step explanation:

Step(i):-

By using trigonometry formulas

a)

cos2∝ = 2 cos² ∝-1

cos∝ = 2 cos² ∝/2 -1

1+ cos∝ = 2 cos² ∝/2

$cos^{2} (\frac{\alpha }{2}) = \frac{1+cos\alpha }{2}$

b)

cos2∝ = 1- 2 sin² ∝

cos∝ = 1- 2 sin² ∝/2

$sin^{2} (\frac{\alpha }{2}) = \frac{1-cos\alpha }{2}$

Step(i):-

Given

$tan\alpha = \frac{sin\alpha }{cos\alpha }$

we know that trigonometry formulas

$sin\alpha = 2sin(\frac{\alpha }{2} )cos(\frac{\alpha }{2} )$

1- cos∝ = 2 sin² ∝/2

Given

$tan(\frac{\alpha }{2} ) = \frac{sin(\frac{\alpha }{2} )}{cos(\frac{\alpha }{2}) }$

put ∝ = 315

$tan(\frac{315}{2} ) = \frac{sin(\frac{315 }{2} )}{cos(\frac{315 }{2}) }$

multiply with ' 2 sin (∝/2) both numerator and denominator

$tan (\frac{315}{2} )= \frac{2sin^{2}(\frac{315)}{2} }{2sin(\frac{315}{2} cos(\frac{315}{2}) }$

Apply formulas

$sin\alpha = 2sin(\frac{\alpha }{2} )cos(\frac{\alpha }{2} )$

1- cos∝ = 2 sin² ∝/2

now we get

$tan (157.5) = \frac{1-cos 315}{sin315}$

b)

$sin^{2} (\frac{\alpha }{2}) = \frac{1-cos\alpha }{2}$

put ∝ = 330° above formula

$sin^{2} (\frac{330 }{2}) = \frac{1-cos (330) }{2}$

$sin^{2} (165) = \frac{1-cos (330) }{2}$

$sin (165) =\sqrt{ \frac{1-cos (330) }{2}}$

c )

$sin^{2} (\frac{\alpha }{2}) = \frac{1-cos\alpha }{2}$

put ∝ = 315° above formula

$sin^{2} (\frac{315 }{2}) = \frac{1-cos (315) }{2}$

$sin^{2} (157.5) = \frac{1-cos (315) }{2}$

d)

cos∝ = 1- 2 sin² ∝/2

put ∝ = 330°

$cos 330 = 1 - 2sin^{2} (\frac{330}{2} )$

cos 330° = 1- 2 sin² (165°)

3 0

3 years ago

Triangle F G E is shown. Angle F E G is a right angle. The length of hypotenuse F G is 18.6 inches and the length of F E is 12 i

Delicious77 [7]

Answer:

Measure of ∠FGE is 40.2°.

Step-by-step explanation:

Refer to the attachment.

Consider ΔFGE. Given that ∠FEG = 90° and ∠FGE is x°.

To find the value of ∠FGE use trigonometric ratios.

Use sine ratio to find the value of ∠FGE.

$\sin \theta=\dfrac{opposite\:side}{hypotenuse\:side}$

Rewriting it in terms of x° as follows,

$\sin x=\dfrac{opposite\:side}{hypotenuse\:side}$

Now find the opposite and hypotenuse side of the angle ∠FGE.

So opposite side of ∠FGE is FE and hypotenuse side of ∠FGE is FG.

Substituting the values,

$\sin x=\dfrac{FE}{FG}$

Given that length of FE is 12 inch and FG is 18.6 inch.

Substituting the value,

$\sin x=\dfrac{12}{18.6}$

To find the value of x, taking inverse sin.

$x=\arcsin \left(\dfrac{12}{18.6}\right)$

Calculating the value,

$x=40.17$

Rounding to nearest tenth the value of angle is 40.2

Therefore measure of ∠FGE is 40.2° .

8 0

2 years ago

I need help in this question please

stepan [7]

The whole wall area including the window is 150 ft squared (15 ft x 10 ft). The window is 50 square feet (5 x 10). Take the whole area and subtract the window area and you have 100 sq ft thats paintable. One can is 50 sq ft so 100/50 is 2 cans of paint needed. Your answer is H.

4 0

2 years ago

Ratios and Proportions

irina1246 [14]

An example of a ratio would be:
1:2
3:4
5:6

An example of a proportion would be:
1/2
3/4
5/6

Hope this helps!

4 0

3 years ago

Read 2 more answers

5+8=6+7 true or false

Romashka-Z-Leto [24]

Answer: True becuase 5+8 equals 13 and 6+7 also equal 13 so that means that they are equal to each other.

Step-by-step explanation: