Hello,
x²/25+y²/9=1
a=5, b=3 c²=a²-b²=25-9=16=4²
Foci are (0,4) and (0,-4)
Answer C
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X² + 8x +y² - 2y -64 =0
We see that the equation has x² and y² . Also we see that coefficients in front of x² and y² are equal. So this is an equation of the circle.
(x² + 8x) +(y² - 2y) -64 =0
(x² + 8x) +(y² - 2y) = 64
We need to complete square for x and y groups, that means it should be written in form (a+b)² or (a-b)².
Expressions in parenthesis we will write as a²+/-2ab+b², to write it after as (a+/-b)², because a²+/-2ab+b² = (a+/-b)²
(x² + 2*4x) +(y² - 2*1y) = 64
(x² + 2*4x+4²) +(y² - 2*1y+1²) = 64+4²+1²
(x+4)² + (y-1)²= 81 Sometimes this is called a standard form of the circle.
(x+4)² + (y-1)²= 9² Sometimes it is required to write like this.
And if you are studying circles,ellipses and hyperbolas, the standard form should look like
Answer:
0.07378
Step-by-step explanation:
We solve using z score formula
z = (x-μ)/σ/√n, where
x is the raw score = 65 inches
μ is the population mean= 64.5 inches
σ is the population standard deviation = 2.99
n = 75
z = 65 - 64.5 /2.99/√75
z = 0.5/0.345255461
z = 1.4482
Probability value from Z-Table:
P(x<25) = 0.92622
P(x>25) = 1 - P(x<25)
= 1 - 92622
= 0.07378
The probability that the mean height for the sample is greater than 65 inches is 0.07378
Answer:
43
Step-by-step explanation:
Vertically opposite angles.
Here,
b=43 (being vertically opposite angles )