Question

I need help with my math practice questions for my test tomorrow, I know how to find the D and R but i hate the one with the questions that contain only x or a square root so if anyone can step by step show me how to find domain and range of
y=x^2+1
and
y=- square root over x+5

Answer 1

@TheSmartOne

Answer 2

y=x^2+1
when x is <0 y is >0 (-x)^2 is positive
for any x then y >0
x = set for real numbers -infinity to infinity

when x = 0 y = 1 the lowest value of y

Answer 3

so y (1, infinity)

Answer 4

y=- square root over x+5
is something missing?

Answer 5

It says y=-\[\sqrt{x+5}\]

Answer 6

Plot
points

Answer 7

that's better you had over

Answer 8

cannot take the rt of a negative (at least for High School) so the minimum value of x is -5

Answer 9

to plot points pick a value of x and calculate the corresponding value for y
eg when x = -5 y =0
when x = 7 y = -rt of 7 + 5 = -rt 12

negative squared is positive and positive squared is positive so for every square root taken there are 2 values the positive and the negative. Here I take it that the value of y is the negative root. need to use one y value for each x value.

Answer 10

Ok thank you!!!