Respuesta :
answer for q1- (a) f(x)=x^2-6x
x^2-6x+9 = y+9
(x-3)^2 = y+9
Vertex: (3,-9)
ill try to figure out the rest till then:)
x^2-6x+9 = y+9
(x-3)^2 = y+9
Vertex: (3,-9)
ill try to figure out the rest till then:)
Answer:
-5; (8, -4); x = 5 or x = -2; x = -8 or x = -9; (4, 3)
Step-by-step explanation:
For the first question,
To write the function in vertex form, we first set it equal to 0:
0 = x²+10x+35
We want to complete the square. Our next step will be to take half of b, which is 10, and square it; add this to each side:
(10/2)² = 5² = 25;
0+25 = x²+10x+35+25
25 = x²+10x+25+35
After rearranging the terms, we write the first three as a square. It will be (x+b/2)²:
25 = (x+5)²+35
Subtract 25 from each side:
25-25 = (x+5)²+35-25
0 = (x+5)²+10
f(x) = (x+5)²+10
This is vertex form. The value of h will be -5.
For the second question,
To find the minimum we find the vertex. We first find the axis of symmetry, using
x = -b/2a
x = --16/2(1) = 16/2 = 8
Next substitute 8 in place of x:
f(8) = 8²-16(8)+60 = 64-128+60 = -64+60 = -4
This makes the vertex, or minimum, (8, -4).
For the third question,
We find the roots by writing the function in factored form. To do this, find factors of c that sum to b:
Factors of -10: -10 and 1 (sum is -9); 10 and -1 (sum is 9); -5 and 2 (sum is -3); 5 and -2 (sum is 3). The ones we want are -5 and 2; this gives us
f(x) = (x-5)(x+2)
Using the zero product property,
x - 5 = 0 or x + 2 = 0
x-5+5 = 0+5 or x+2-2 = 0-2
x = 5 or x = -2
For the fourth question,
We want to find the roots again, by writing in factored form:
Factors of 72: 1 and 72 (sum to 73); 2 and 36 (sum to 38); 3 and 24 (sum of 27); 4 and 18 (sum of 22); 6 and 12 (sum of 18); 8 and 9 (sum of 17)
The ones we want are 8 and 9:
f(x) = (x+8)(x+9)
Using the zero product property,
x+8 = 0 or x+9 = 0
x+8-8 = 0-8 or x+9-9 = 0-9
x = -8 or x = -9
For the fifth question, we find the minimum by finding the vertex. First find the axis of symmetry:
x = -b/2a = --8/2(1) = 8/2 = 4
Substitute 4 in for x:
f(4) = 4²-8(4)+19 = 16-32+19 = -16+19 = 3
The vertex is (4, 3).