Answer:
(6, 9 ) and r = 3
Step-by-step explanation:
The equation of a circle in standard form is
(x - h)² + (y - k)² = r²
where (h, k) are the coordinates of the centre and r is the radius
Given
x² + y² - 12x - 18y + 108 = 0
Rearrange the x- terms and the y- terms together and subtract 108 from both sides, that is
x² - 12x + y² - 18y = - 108
To obtain standard form use the method of completing the square
add ( half the coefficient of the x and y terms )² to both sides
x² + 2(- 6)x + 36 + y² + 2(- 9)y + 81 = - 108 + 36 + 81
(x - 6)² + (y - 9)² = 9 ← in standard form
with centre = (6, 9 ) and r =
= 3
Answer:
90 in²
Step-by-step explanation:
The figure's area is that of four right triangles, each with legs of 6 in and 7.5 in. The area of each triangle is half the product of the leg lengths, so is ...
triangle area = (1/2)(6 in)(7.5 in)
Then the area of 4 of those triangles is ...
figure area = 4 · triangle area = 2(6 in)(7.5 in) = 90 in²
Answer:
36
Step-by-step explanation:
Since f(x) varies directly with x, f(x) can be expressed alternatively as \[f(x) = k * x\] where k is a constant value.
Given that f(x) is 72 when the value of x is 6.
This implies, \[72 = k * 6\]
Simplifying and rearranging the equation to find the value of k:
k = \frac{72}{6}
Hence k = 12
Or, \[f(x) = 12 * x\]
When x = 3, \[f(x) = 12 *3 \]
Or in other words, the value of f(x) when x=3 is 36