Friday

March 27, 2015

March 27, 2015

Posted by **toni** on Tuesday, October 8, 2013 at 12:41pm.

For what value of c does the equation have one real root? Hint using the values of a and b found in the equation, solve D = 0 for c.

Consider the quadratic expression X^2 + 4x + c = 0.

- algebra -
**Jai**, Tuesday, October 8, 2013 at 12:53pmRecall the formula for discriminant. For a quadratic equation in the general form, ax^2 + bx + c = 0,

D = b^2 - 4ac

if

D = 0 : real, equal/double root

D > 0 : two real, unequal roots

D < 0 : two imaginary roots

Since we're required to have one real root, we equate D to zero, and solve for the unknown, c.

x^2 + 4x + c = 0

a = 1

b = 4

c = ?

Substituting to the discriminant formula, (D = 0)

0 = 4^2 - 4*1*c

0 = 16 - 4c

4c = 16

c = 4

Hope this helps~ :3

**Answer this Question**

**Related Questions**

algebra - Im lost i dont know how to do this can someone show me step by step ...

algebra - please help im lost the instructions are to solve by using thee ...

Algebra - Can someone show me step by step how to do this problem to have an ...

math/algebra - solve each of the following systems by substitution. 16) 5x -2y...

Math - I am really have a tough time trying to solve this problem. I think my ...

Algebra 1--Step-by-Step - Can someone show me how to solve these step-by-step? ...

math - My problem I have involves a method that requires using the quadratic ...

Math - can someone sow me step by step how to evaluate the integral of the ...

Pre-Algebra [urgent!] - I can't find the solution to this problem; can someone ...

Algebra 1 (Step-by-Step) - Will someone explain how to solve this? Write each ...