Question

Which of the following coordinates of points belong to the solution set of the inequality y<2x²+5×-1 ??

A. (-3,2)
B. (-2,9)
C. (1,6)
D. (3,1)

Answer 1

Solution. Check the inequality for each point. For A(-3,2)

$$2<2(-3)^2+5(-3)-1$$ $$2<2$$

The inequality is not satisfied.

For B(-2,9)

$$2<2(-2)^2+5(-2)-1$$

$$2<-3$$

The inequality is not satisfied.

For C(1,6)

$$6<2\times1^2+5\times1-1$$

$$6<6$$

The inequality is not satisfied.

For D(3,1)

$$1<2\times3^2+5\times3-1$$

$$1<32$$

The inequality is satisfied.

Answer. D. (3,1)