Answer:
f(x) = x³ - 5x² - 9x + 45
Step-by-step explanation:
Given x = a, x = b are the zeros of a polynomial, then
(x - a), (x - b) are the factors and f(x) is the product of the factors.
Here the zeros are x = - 3, x = 3 and x = 5, thus
(x + 3), (x - 3) and (x - 5) are the factors and
f(x) = (x + 3)(x - 3)(x - 5) ← expand the first pair of factors using FOIL
= (x² - 9)(x - 5) ← distribute
= x³ - 5x² - 9x + 45
Answer:
The slope of the line is -3/2 or -1.5
Step-by-step explanation:
y2-y1/x2-x1
-1-2/2-0=
-3/2 or -1.5
Answer:
12.1 cm
Step-by-step explanation:
Using the law of sines, we can find angle C. Then from the sum of angles, we can find angle B. The law of sines again will tell us the length AC.
sin(C)/c = sin(A)/a
C = arcsin((c/a)sin(A)) = arcsin(8.2/13.5·sin(81°)) ≈ 36.86°
Then angle B is ...
B = 180° -A -C = 180° -81° -36.86° = 62.14°
and side b is ...
b/sin(B) = a/sin(A)
b = a·sin(B)/sin(A) = 13.5·sin(62.14°)/sin(81°) ≈ 12.0835
The length of AC is about 12.1 cm.
_____
<em>Comment on the solution</em>
The problem can also be solved using the law of cosines. The equation is ...
13.5² = 8.2² +b² -2·8.2·b·cos(81°)
This is a quadratic in b. Its solution can be found using the quadratic formula or by completing the square.
b = 8.2·cos(81°) +√(13.5² -8.2² +(8.2·cos(81°))²)
b = 8.2·cos(81°) +√(13.5² -(8.2·sin(81°))²) . . . . . simplified a bit
