How do you graph #f(x) = 3sqrtx + 2 #?

1 Answer
Nov 16, 2017

You take a few critical points, and graph.

Explanation:

Normally we choose the Y-intercept (when x=0) and the X-intercept (when y=0), and x=1, x=-1, x=2, etc. Close values to zero.

Let's calculate the y-intercept first.

x=0
3#sqrt(0)#+2=0+2=2 Point (0, 2)

y-intercept

y=0

0=3#sqrt(x)#+2
-2=3#sqrt(x)#
#(-2/3)#=#sqrt(x)#
#x#=#4/9# Point (#4/9#, 0)

x=1

3#sqrt(1)#+2=5 Point (1, 5)

x=-1

3#sqrt(-1)#+2= ? Point does not exist because square root
of a negative number does not exist.

Pretty soon we can see that the graph will start AFTER zero and nothing before. Then it will be a curve low to high as it progresses right. Graph below:

graph{3sqrt(x)+2 [-10, 10, -5, 5]}