First, notice that:
![2\tan (\frac{x}{2})=2\cdot(\pm\sqrt[]{\frac{1-cosx}{1+\cos x})}](https://tex.z-dn.net/?f=2%5Ctan%20%28%5Cfrac%7Bx%7D%7B2%7D%29%3D2%5Ccdot%28%5Cpm%5Csqrt%5B%5D%7B%5Cfrac%7B1-cosx%7D%7B1%2B%5Ccos%20x%7D%29%7D)
And in the denominator we have:
then, we have on the original expression:
![\begin{gathered} \frac{2\tan(\frac{x}{2})}{1+\tan^2(\frac{x}{2})}=\frac{2\cdot\pm\sqrt[]{\frac{1-\cos x}{1+cosx}}}{\frac{2}{1+\cos x}}=\frac{2\cdot(\pm\sqrt[]{1-cosx})\cdot(1+\cos x)}{2\cdot(\sqrt[]{1+cosx})} \\ =(\sqrt[]{1-\cos x})\cdot(\sqrt[]{1+\cos x})=\sqrt[]{(1-\cos x)(1+\cos x)} \\ =\sqrt[]{1-\cos^2x}=\sqrt[]{\sin^2x}=\sin x \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20%5Cfrac%7B2%5Ctan%28%5Cfrac%7Bx%7D%7B2%7D%29%7D%7B1%2B%5Ctan%5E2%28%5Cfrac%7Bx%7D%7B2%7D%29%7D%3D%5Cfrac%7B2%5Ccdot%5Cpm%5Csqrt%5B%5D%7B%5Cfrac%7B1-%5Ccos%20x%7D%7B1%2Bcosx%7D%7D%7D%7B%5Cfrac%7B2%7D%7B1%2B%5Ccos%20x%7D%7D%3D%5Cfrac%7B2%5Ccdot%28%5Cpm%5Csqrt%5B%5D%7B1-cosx%7D%29%5Ccdot%281%2B%5Ccos%20x%29%7D%7B2%5Ccdot%28%5Csqrt%5B%5D%7B1%2Bcosx%7D%29%7D%20%5C%5C%20%3D%28%5Csqrt%5B%5D%7B1-%5Ccos%20x%7D%29%5Ccdot%28%5Csqrt%5B%5D%7B1%2B%5Ccos%20x%7D%29%3D%5Csqrt%5B%5D%7B%281-%5Ccos%20x%29%281%2B%5Ccos%20x%29%7D%20%5C%5C%20%3D%5Csqrt%5B%5D%7B1-%5Ccos%5E2x%7D%3D%5Csqrt%5B%5D%7B%5Csin%5E2x%7D%3D%5Csin%20x%20%5Cend%7Bgathered%7D)
therefore, the identity equals to sinx
(Problems 1b and 2b are cut off in the photo)
1a Problem:
(-3,1)
(-3,5)
(-7,1)
2a Problem:
(6,2)
(3,5)
(10,7)
*Psst, I need one more brainliest answer to rank up, so if you gave that to me, it would be very appreciated, thanks :)*
Answer:
The value of x is 21.
Step-by-step explanation:
Since this is a right angle triangle, you can apply Pythagoras theorem, side² + side² = hypo² :
(x + 3)² + 10² = (x + 5)²
x² + 6x + 9 + 100 = x² + 10x + 25
x² + 6x + 109 - x² - 10x - 25 = 0
-4x + 84 = 0
-4x = -84
4x = 84
x = 84 ÷ 4
x = 21 units
Answer:
107.50
Step-by-step explanation:
Given the following :
Midpoint (S)____F
S y 93 95 97 99 101 103 105 107 109 111 f 19 25 38 17 12 10 5 4 4 2
Calculating the mean and standard deviation using a calculator :
The mean(m) of the data above = 98.12
Standard deviation (sd) = 4.02
Proportion = 99% of population
From z table = 2.33
Using :
Zscore =(x - m) / sd
2.33 = (x - 98.12) / 4.02
2.33 * 4.02 = x - 98.12
9.3666 = x - 98.12
9.3666 + 98.12= x
x = 107.4866
X = 107.50
