Determine the number of possible positive and negative real roots of the equation:
x - 4x + 5x² + 9x² + 2x 8
a 2 or 0 negative roots; 3 or 1 positive roots
b. 5, 3, or 1 negative roots;
4, 2 or 0 positive roots
c.
d.
2 or 1 neative roots; 3 or 2 positive roots
3 or 1 negative roots; 2 or 0 positive roots
9514 1404 393
Answer:
π square inches
Step-by-step explanation:
The area of the whole circle is ...
A = πr²
A = π(2 in)² = 4π in²
A 90° sector is 1/4 of the circle, so its area is ...
(1/4)(4π in²) = π in²
We want to recast the equation into the standard form equation for a circle centered at (h, k) with radius r. That equation is
... (x -h)² + (y -k)² = r²
Start by completing the square for both x-terms and y-terms.
... x² - 4x + y² + 4y = k
To do that, add the squares of half the coefficients of the x- and y-terms.
... x² - 4x + (-2)² + y² + 4y + 2² = k + (-2)² + 2²
... (x -2)² + (y +2)² = k + 8 = r² . . . . . this is now equal to the square of the radius, so we have
... k + 8 = 6² = 36
Subtracting 8 gives
... k = 28 . . . . . . . matches selection D)
