# Math Help - Exponential functions

1. ## Exponential functions

1) R(x)=x^2-x-12 Find the graph, intercepts, domain and range
x+5

2) g(x)=5^x -3
a) What is g(-1)?What Point is on the graph of g?
b) If g(x)= 122. what is x? what point is on the graph?

Hi If Any One caN heLp Me sOlve these two questions ThaNkzZz !

2. Sorry don't know the first one or part a of the second one.

b) If g(x)= 122. what is x? what point is on the graph?

122 = x^3 - 3
+3 +3

125 = x^3

x=5

3. Originally Posted by zxc
1) R(x)=x^2-x-12 Find the graph, intercepts, domain and range
x+5

2) g(x)=5^x -3
a) What is g(-1)?What Point is on the graph of g?
b) If g(x)= 122. what is x? what point is on the graph?

Hi If Any One caN heLp Me sOlve these two questions ThaNkzZz !
1) R(x) = x^2-x-2 is a quadratic function.
I am not sure about what it is asking when it say find the graph. But graphically saying, it is a parabola "open up".
x-intercept(s): solve R(x) = 0 for x.
y-intercept: It is when x = 0. So just substitute 0 into x.
Domain: is all reals since parabola is very "nice". In other words, R(x) is defined on all the reals.
Range: it will be anything greater than or equal to its minimum. Algebraically, you can write R(x) in vertex form by "completing square" to obtain its vertex, that will give you what you need. Or just simply graph it using a graphing calculator.

2a)
$g(-1)=5^{-1} -3 = \frac{1}{5} -3=-2.8$
The point on the graph will be (-1, -2.8)

2b) $g(x) = 5^{x} -3 = 122$
So, $5^{x}=125$
Then, either by using "log" or observation, x = 3.

4. THaNkzZz GuYzZz !