Question

Find the range for f(x) = x2 + 1, for x < 0.

y ≥ 1
y > 1
y < 1
y ≤ 1
A?

Answer 1

\[x<0 \\ \text{ multiply } x \text{ on both sides } x \cdot x >0 \cdot x \\ \text{ do you know why I change the direction of the inequality ? }\]

Answer 2

hint: what does x<0 mean in words

Answer 3

x less than 0?

Answer 4

or x is negative
if you multiply both sides of an inequality by a negative number you have to change the direction of the inequality

Answer 5

\[x<0 \\ x \cdot x> 0 \cdot x \\ x^2 >0 \\ \text{ now add 1 on both sides } x^2+1>0+1\]

Answer 6

\[x^2+1>1 \]

Answer 7

remember x^2+1 is y since we had f(x)=x^2+1

Answer 8

ohh ok thank you!

Answer 9

np