Posted by Tomtom on Thursday, November 17, 2011 at 6:52pm.
Help trig question involving discriminant?
a)Find the value of the discriminant.
b)Use any method to find the real roots of the equation if they exist.
- Trigonometry - Steve, Friday, November 18, 2011 at 12:05pm
surely you got as far as evaluating the discriminant: b^2 - 4ac = 7 - 0 = 7
factor: x(2x+7) = 0
a product is zero if any factor is zero. So,
x=0 or (2x+7) = 0
so, the roots are 0 and -7/2
Using the quadratic formula, we have
x = [-7 +/- sqrt(49-0)]/4
= [-7 +/- 7]/2
= 0 or -7/2
Completing the square,
2(x^2 + 7/2 x + (7/4)^2) - 2(7/4)^2 = 0
2(x + 7/4)^2 = 2(7/4)^2
x + 7/4 = (7/4)^2 = 49/16
x = -7/4 +/- 7/4
= 0 or -7/2
Answer This Question
More Related Questions
- math - I HAVE THESE ANSWERS FOR THE PROBLEMS. COULD YOU DOUBLE CHECK PLEASE, ...
- math - Could you please solve so I can double check my answers for the practice ...
- Calculus/pre-trig - Write the formula for the discriminant. State the types of ...
- Math - determine the value(s) of k which the equation x^2+kx+9=0 will have a) ...
- math - How many real roots exist if the discriminant of the equation=0?
- Math - determine the value(s) of k which a quadratic equation x^2+kx+9=0 will ...
- math - Which statement concerning the equation x^2+2=x is true? Its discriminant...
- Algebra Problem - State the value of the discriminant and the number of real ...
- algebra - What would be the discriminant for this equation: x^2-2x+12=0 How many...
- Math - For the following equation, state the value of the discriminant and then ...