Use following substitutions:
<span>r cosθ = x </span>
<span>r sinθ = u </span>
<span>r² = x² + y² </span>
<span>r = 8 cosθ + 4 sinθ </span>
<span>Multiply both sides by r </span>
<span>r² = 8 r cosθ + 4 r sinθ </span>
<span>x² + y² = 8x + 4y </span>
<span>This is equation of circle. We can put in standard form: </span>
<span>x² − 8x + y² − 4y = 0 </span>
<span>x² − 8x + 16 + y² − 4y + 4 = 16 + 4 </span>
<span>(x − 4)² + (y − 2)² = 20 </span>
<span>Circle centered at point (4, 2) with radius = √20</span><span />
Given:
15. 
17. 
19. 
To find:
The values of the given logarithms by using the properties of logarithms.
Solution:
15. We have,
Using property of logarithms, we get
![[\because \log_aa=1]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%5Clog_aa%3D1%5D)
Therefore, the value of is 1.
17. We have,
Using properties of logarithms, we get
![[\because \log_a\dfrac{m}{n}=-\log_a\dfrac{n}{m}]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%5Clog_a%5Cdfrac%7Bm%7D%7Bn%7D%3D-%5Clog_a%5Cdfrac%7Bn%7D%7Bm%7D%5D)
Therefore, the value of is -1.
19. We have,
Using property of logarithms, we get
![[\because a^{\log_ax}=x]](https://tex.z-dn.net/?f=%5B%5Cbecause%20a%5E%7B%5Clog_ax%7D%3Dx%5D)
Therefore, the value of is 100.
Answer:
y = -1/2 x + 2
Step-by-step explanation:
Which of the following equations describes the line shown below? Check all
that apply.
(-4, 4)
(2, 1)
The standard equation of a line is y = mx,+b
m is the slope
b is he y-inttercept
Get the slope
Slope m = y2-y1/x2-x1
Substitute the coordinate
M = 1-4/2-(-4)
M = -3/6
M = -1/2
Substitute m= -1/2 and (2,1) into y = mx+b
1 = -1/2(2)+b
1 = -1+b
b = 1+1
b=2
Get the equation
Recall y =mx+b
y = -1/2 x + 2
The y intercept is -4 and the slope is 2
