SOLUTION: please help i got my portfolio to be handed in tomorrow by 2pm and I missed a class on parabolas i need to find the x intercept and y intercept, can someone please help me? f(x) =

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: please help i got my portfolio to be handed in tomorrow by 2pm and I missed a class on parabolas i need to find the x intercept and y intercept, can someone please help me? f(x) =      Log On


   

Question 1061430: please help i got my portfolio to be handed in tomorrow by 2pm and I missed a class on parabolas i need to find the x intercept and y intercept, can someone please help me? f(x) = 4x^2 + 4x + 6
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+f%28x%29+=+4x%5E2+%2B+4x+%2B+6+
You find the y-intercept by making +x+=+0+
+f%28x%29+=+f%280%29+
+f%280%29+=+4%2A0%5E2+%2B+4%2A0+%2B+6+
+f%280%29+=+6+
The y-intercept is at ( 0, 6 )
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You find the x-intercepts by making +f%28x%29+=+0+
+0+=+4x%5E2+%2B+4x+%2B+6+
divide both sides by +2+
+0+=+2x%5E2+%2B+2x+%2B+3+
Use the quadratic formula
when the form is:
+f%28x%29+=+a%2Ax%5E2+%2B+b%2Ax+%2B+c+
+x+=+%28+-b+%2B-+sqrt%28+b%5E2+-+4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
+a+=+2+
+b+=+2+
+c+=+3+
+x+=+%28+-2+%2B-+sqrt%28+2%5E2+-+4%2A2%2A3+%29%29%2F%282%2A2%29+
+x+=+%28+-2+%2B-+sqrt%28+4+-+24+%29%29%2F4+
+x+=+%28+-2+%2B-+sqrt%28+-20+%29+%29%2F4+
+x+=+%28+-2+%2B+2%2Asqrt%285%29%2Ai+%29+%2F+4+
+x+=+-1%2F2+%2B+%28+sqrt%285%29%2F2+%29%2Ai+
and, also:
+x+=+-1%2F2+-+%28+sqrt%285%29%2F2+%29%2Ai+
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The roots in this case are a pair
of imaginaries called a complex conjugate pair.
There are no actual intersections with the x-axis.
------------------------------------------------
Here's the plot so you can see the y-intercept,
and the fact that there is no intersection with x-axis
+graph%28+400%2C+500%2C+-5%2C+5%2C+-2%2C+15%2C+4x%5E2+%2B+4x+%2B+6+%29+