MATH I NEED HELP PLEASE
posted by Queta on .
1. The range of f ( x ) = ax + b is the set of all real numbers given that a and b are real numbers. Which produces a counter examples to her statement ?
A. a = 0
B. b = 0
C. a < 0
D. b < 0
My answer I came up with was b or c I was not sure.
2. f ( x ) =  6
x 1 and g ( x ) 4 x^2
select the solution for ( f +g ) ( x )
A.  6 x  1 + 4 x ^ 2
B.  24 x^3  4 x^2
C. 24 x^2  1
D.  6 x  1 24 x^2
My answer I came up with is C.
3. f ( x ) =  6 x  1 and g ( x ) = 4 x^2 select the solution for ( f g )( x )
A.  6 x  1 + 4 x^2
B. 24 x^3 4 x^2
C.  24 x^2  1
D . 24 x^5
My answer I came up with was either C or D. was not sure.
4. The profit ( p) , in dollars , for a company is modeled by the function P ( x ) =  750 x^2 + 15,000 x , Where x is the number of items produced. For which x is the number of items produced. For which values of x will the company lose money ?
A. x > 20
B. 2 < x < 10
C. 10 < x < 20
D. x < 2
My answer I came up with was A.
5. The function h ( x ) = 1 / 98 x^2 describes h ( x ) , the height of part of a roller coaster track , where x is the horizontal distance in feet from the center of this section of the track, The towers that support this part of the track are the same height and are 150 feet apart, which is the best estimate of the height of the towers ?
A. 121.2 feet
B. 85. 7 feet
C. 229. 6 feet
D. 57.4 feet
My answer I came up with was C. I am not sure .

#1 is (A) because then f(x) = 0x+b = b
and the range is just y=b
#2 (f+g)(x) = f(x) + g(x). So, (A)
#3 (fg)(x) = f(x) * g(x) = (6x1)(4x^2). So, (B)
#4 P(x) =  750 x^2 + 15,000 x = 750x(20x)
This is a parabola with roots at x=0,20
Since it opens downward, P(x) is positive only between the roots.
So, (A)
#5 Since the poles are 150 apart, 75<=x<=75
h(75) = 1/98 x^2 = 1/98 * 75^2 = 57.4
So, (D) 
Thank you Stevie

find the function h(x)=1/98 x^2