Answer:
Step-by-step explanation:
Given expression is,
To prove this identity we will take the right side of the identity,
![=\frac{1}{2}[\frac{2(1-\text{tan}^2\frac{A}{2})}{2tan\frac{A}{2}}]](https://tex.z-dn.net/?f=%3D%5Cfrac%7B1%7D%7B2%7D%5B%5Cfrac%7B2%281-%5Ctext%7Btan%7D%5E2%5Cfrac%7BA%7D%7B2%7D%29%7D%7B2tan%5Cfrac%7BA%7D%7B2%7D%7D%5D)
[Since 
]
= cot A
Hence right side of the equation is equal to the left side of the equation.
Answer:
23. x = 4; DE = 44
24. x = 25; DS = 28
Step-by-step explanation:
23. Point S is the midpoint of DE, so ...
DS = SE
3x +10 = 6x -2
12 = 3x . . . . . . . . . add 2-3x
4 = x . . . . . . . . . . . divide by 3
Then DS has length ...
DS = 3x +10 = 12 +10 = 22
and DE is twice that length, so ...
DE = 44
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24. DS is half the length of DE, so is ...
DS = DE/2 = 56/2
DS = 28
Then x can be found from ...
DS = x +3
28 -3 = x = 25 . . . . . substitute value for DS
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<em>Comment on problem 24</em>
Sometimes it is easier to work parts of a problem out of sequence. Here, finding DS first makes finding x easier.
1. C -9
2. B 7.5
3. A -4
4. C 65
Answer:
1.1, -5
Step-by-step explanation:
53 - 9y = 1
from equation i
53-9y = 1
-9y= 1-53 = -52
y = -52/-9= 52/9 = 5⁷/₉
-7.2 + 2y = -5
add 7.2 to both sides
2y= -5+7.2 = 2.2
y= 2.2/2 = 1.1
