Answer:
Step-by-step explanation:
you could create an equation which would be 288= 90 + 20(x)
x = the amount of days needed
answer would be 10 days
Given:
![\cos 15^{\circ}](https://tex.z-dn.net/?f=%5Ccos%2015%5E%7B%5Ccirc%7D)
To find:
The exact value of cos 15°.
Solution:
![$\cos 15^{\circ}=\cos\frac{ 30^{\circ}}{2}](https://tex.z-dn.net/?f=%24%5Ccos%2015%5E%7B%5Ccirc%7D%3D%5Ccos%5Cfrac%7B%2030%5E%7B%5Ccirc%7D%7D%7B2%7D)
Using half-angle identity:
![$\cos \left(\frac{x}{2}\right)=\sqrt{\frac{1+\cos (x)}{2}}](https://tex.z-dn.net/?f=%24%5Ccos%20%5Cleft%28%5Cfrac%7Bx%7D%7B2%7D%5Cright%29%3D%5Csqrt%7B%5Cfrac%7B1%2B%5Ccos%20%28x%29%7D%7B2%7D%7D)
![$\cos \frac{30^{\circ}}{2}=\sqrt{\frac{1+\cos \left(30^{\circ}\right)}{2}}](https://tex.z-dn.net/?f=%24%5Ccos%20%5Cfrac%7B30%5E%7B%5Ccirc%7D%7D%7B2%7D%3D%5Csqrt%7B%5Cfrac%7B1%2B%5Ccos%20%5Cleft%2830%5E%7B%5Ccirc%7D%5Cright%29%7D%7B2%7D%7D)
Using the trigonometric identity: ![\cos \left(30^{\circ}\right)=\frac{\sqrt{3}}{2}](https://tex.z-dn.net/?f=%5Ccos%20%5Cleft%2830%5E%7B%5Ccirc%7D%5Cright%29%3D%5Cfrac%7B%5Csqrt%7B3%7D%7D%7B2%7D)
![$=\sqrt{\frac{1+\frac{\sqrt{3}}{2}}{2}}](https://tex.z-dn.net/?f=%24%3D%5Csqrt%7B%5Cfrac%7B1%2B%5Cfrac%7B%5Csqrt%7B3%7D%7D%7B2%7D%7D%7B2%7D%7D)
Let us first solve the fraction in the numerator.
![$=\sqrt{\frac{\frac{2+\sqrt{3}}{2}}{2}}](https://tex.z-dn.net/?f=%24%3D%5Csqrt%7B%5Cfrac%7B%5Cfrac%7B2%2B%5Csqrt%7B3%7D%7D%7B2%7D%7D%7B2%7D%7D)
Using fraction rule: ![\frac{\frac{a}{b} }{c}=\frac{a}{b \cdot c}](https://tex.z-dn.net/?f=%5Cfrac%7B%5Cfrac%7Ba%7D%7Bb%7D%20%7D%7Bc%7D%3D%5Cfrac%7Ba%7D%7Bb%20%5Ccdot%20c%7D)
![$=\sqrt{\frac {2+\sqrt{3}}{4}}](https://tex.z-dn.net/?f=%24%3D%5Csqrt%7B%5Cfrac%20%7B2%2B%5Csqrt%7B3%7D%7D%7B4%7D%7D)
Apply radical rule: ![\sqrt[n]{\frac{a}{b}}=\frac{\sqrt[n]{a}}{\sqrt[n]{b}}](https://tex.z-dn.net/?f=%5Csqrt%5Bn%5D%7B%5Cfrac%7Ba%7D%7Bb%7D%7D%3D%5Cfrac%7B%5Csqrt%5Bn%5D%7Ba%7D%7D%7B%5Csqrt%5Bn%5D%7Bb%7D%7D)
![$=\frac{\sqrt{2+\sqrt{3}}}{\sqrt{4}}](https://tex.z-dn.net/?f=%24%3D%5Cfrac%7B%5Csqrt%7B2%2B%5Csqrt%7B3%7D%7D%7D%7B%5Csqrt%7B4%7D%7D)
Using
:
![$=\frac{\sqrt{2+\sqrt{3}}}{2}](https://tex.z-dn.net/?f=%24%3D%5Cfrac%7B%5Csqrt%7B2%2B%5Csqrt%7B3%7D%7D%7D%7B2%7D)
![$\cos 15^\circ=\frac{\sqrt{2+\sqrt{3}}}{2}](https://tex.z-dn.net/?f=%24%5Ccos%2015%5E%5Ccirc%3D%5Cfrac%7B%5Csqrt%7B2%2B%5Csqrt%7B3%7D%7D%7D%7B2%7D)
<h2>27 inches³</h2>
Step-by-step explanation:
volume of cude = side³
= 3³
= 3×3×3
= 27 inches³
<h2>FOLLOW ME</h2>
Answer:
10.25
Step-by-step explanation:
The slope of AC is given by the slope formula:
m = (y2 -y1)/(x2 -x1)
m = (-4 -1)/(3 -(-1)) = -5/4
Then the slope of CB is the opposite reciprocal, 4/5. The equation of line CB in point-slope form is ...
y -k = m(x -h) . . . . . . line with slope m through point (h, k)
y -(-4) = 4/5(x -3) . . . . line CB
When y = 1 (to match the y-value of A), then ...
1 +4 = 4/5(x -3)
5(5/4) = (x -3) . . . . . multiply by 5/4
6.25 +3 = x = 9.25 . . . . add 3
Point B is (9.25, 1).
The length of the hypotenuse is ...
9.25 -(-1) = 10.25