Quadratic Equations Practice 2: Formula and Discriminant

Section A: Formula Practice

Question 1mcq

For

x^2-5x+6=0

, what are

a,b,c

?

A.

a=1,b=-5,c=6

B.

a=1,b=5,c=6

C.

a=-1,b=-5,c=6

D.

a=1,b=-5,c=-6

Question 2mcq

Using the quadratic formula, the roots of

x^2+4x+1=0

are:

A.

-2\pm\sqrt{3}

B.

2\pm\sqrt{3}

C.

-4\pm\sqrt{3}

D.

-2\pm2\sqrt{3}

Question 3mcq

Simplify the roots from

x=\frac{6\pm\sqrt{48}}{4}

.

A.

\frac{3\pm2\sqrt{3}}{2}

B.

\frac{6\pm4\sqrt{3}}{4}

C.

3\pm2\sqrt{3}

D.

\frac{3\pm\sqrt{3}}{2}

Question 4mcq

The equation

2x^2-4x-1=0

has roots:

A.

1\pm\frac{\sqrt{6}}{2}

B.

1\pm\sqrt{6}

C.

2\pm\sqrt{6}

D.

\frac{1\pm\sqrt{6}}{2}

Question 5mcq

Find the discriminant of

x^2-6x+9=0

.

A.

0

B.

36

C.

72

D.

-36

Section B: Discriminant Reasoning

Question 6mcq

For

3x^2+2x-5=0

, what is

D

?

A.

64

B.

-56

C.

56

D.

4

Question 7mcq

If the discriminant of a quadratic equation is negative, its roots are:

A.not real

B.real and equal

C.real and distinct

D.always rational

Question 8mcq

The equation

x^2+2x+5=0

has what nature of roots?

A.No real roots

B.Two real distinct roots

C.Two real equal roots

D.One positive root only

Question 9mcq

Find

k

if

x^2-4x+k=0

has equal roots.

A.

4

B.

-4

C.

2

D.

8

Question 10mcq

For

2x^2+kx+8=0

to have real and equal roots, which value of

k

is possible?

A.

8

B.

4

C.

16

D.

2