Step-by-step explanation:
To find out y intercept of any function, we plug in 0 for x and solve for y
For any function y=ab^x + c
The horizontal asymptote at y=c
Now we check each function
[tex]f(x)= 7^x -4[/tex]
Plug in 0 for x to find y intercept
[tex]f(0) = 7^0 -4 = 1 -4 = -3[/tex]
y intercept at (0,-3)
Horizontal asymptote at y=c , here c= -4
So horizontal asymptote at y = -4 and y intercept at (0,-3)
[tex]f(x)= 3^{x+2} +4[/tex]
Plug in 0 for x to find y intercept
[tex]f(0) = 3^{0+2}+4 = 9+4= 13[/tex]
y intercept at (0,13)
Horizontal asymptote at y=c , here c= 4
So horizontal asymptote at y = 4 and y intercept at (0,13)
[tex]f(x)= 9^{x+1} -4[/tex]
Plug in 0 for x to find y intercept
[tex]f(0) = 9^{0+1}-4 = 9-4= 5[/tex]
y intercept at (0,5)
Horizontal asymptote at y=c , here c=-4
So horizontal asymptote at y = -4 and y intercept at (0,5)
[tex]f(x)= 2^x+4[/tex]
Plug in 0 for x to find y intercept
[tex]f(0)=2^0+4=5[/tex]
y intercept at (0,5)
Horizontal asymptote at y=c , here c= 4
So horizontal asymptote at y = 4 and y intercept at (0,5)