SOLUTION: What is the value of the discriminant of the polynomial below? 4x^2 + 7x + 4

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Question 145003: What is the value of the discriminant of the polynomial below?
4x^2 + 7x + 4
Found 2 solutions by solver91311, jim_thompson5910:
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!
Your polynomial is in the form ax%5E2%2Bbx%2Bc, where a=4, b=7, and c=4. The discriminant is the value of the portion of the quadratic formula under the radical. The quadratic formula is: x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+, so the discriminant is: b%5E2-4ac. Just substitute the values for a, b, and c and do the arithmetic.

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
From 4x%5E2%2B7x%2B4 we can see that a=4, b=7, and c=4


D=b%5E2-4ac Start with the discriminant formula


D=%287%29%5E2-4%284%29%284%29 Plug in a=4, b=7, and c=4


D=49-4%284%29%284%29 Square 7 to get 49


D=49-64 Multiply 4%284%29%284%29 to get %2816%29%284%29=64


D=-15 Subtract 64 from 49 to get -15

So the discriminant is D=-15