A. x intercepts are where the graph hits the x axis or where f(x)=0
0=2x^2-x-10
solve
hmm
we can use the ac method
multiply 2 and -10 to get -20
what 2 numbers muliply to get -20 and add to get -1 (the coefint of the x term)
-5 and 4
split the midd into that
0=2x^2+4x-5x-10
group
0=(2x^2+4x)+(-5x-10)
factor
0=2x(x+2)-5(x+2)
undistribute
0=(x+2)(2x-5)
set each to 0
0=x+2
0=-2
0=2x-5
5=2x
5/2=x
x intercepts are at x=-2 and 5/2 or the points (-2,0) and (5/2,0)
B. ok, so for f(x)=ax^2+bx+c
if a>0, then the parabola opens up and the vertex is a minimum
if a<0 then the parabola opens down and the vertex is a max
f(x)=2x^2-x-10
2>0
opoens up
vertex is minimum
ok, the vertex
the x value of the vertex in f(x)=ax^2+bx+c= is -b/(2a)
the y value of the vertex is f(-b/(2a)) so
given
f(x)=2x^2-x-10
a=2
b=-1
-b/2a=-(-1)/(2*2)=1/4
f(1/4)=2(1/4)^2-(1/4)-10
f(1/4)=2(1/16)-1/4-10
f(1/4)=1/8-1/4-10
f(1/4)=1/8-2/8-80/8
f(1/4)=-81/8
so the vertex is (1/4,-81/8) or (0.25,-10.125)
C. graph the x intercepts and the vertex
the vertex is min and the graph goes through the x intercepts
Answer:
maybe do the math
Step-by-step explanation:
Multiply total students by 2/3 to find how many like math:
Like math = 120 x 2/3 = 240/3 = 80 total students like math
Multiply total students by 3/5 to find number of boys:
120 x 3/5 = 360/5 = 72 boys
A) number of girls = total students - boys = 120 -72 = 48 girls
B) from above 80 students like math
C) number of boys that like math = number of students that like math minus girls that like math: 80- 35 = 35 boys like math
Answer:
The rule for the linear function will be:
Step-by-step explanation:
We know that linear function can be represented using the slope-intercept formula
y = mx+b
where m is the slope and b is the y-intercept
Given the function is linear
Taking two points from the table to determine the slope
Using the point-slope form of the line equation
where m is the slope of the line and (x₁, y₁) is the point
substituting the values m = -2 and the point (1, 3)
adding 3 to both sides
or
Therefore, the rule for the linear function will be:
To solve for C, you have to get both of the numbers with a C on the same side. So, subtract the 5c from the right side onto the left side.
Then, divide by 3 on each side.
So, c = 7.
