Find the vertex of the parabola formed by the following quadratic function: y = 7x2 + 21x – 1
Answer

(-2, -15)

(2, 69)

(1, 27)

(-3/2, -67/4)

Question

Find the vertex of the parabola formed by the following quadratic function: y = 7x2 + 21x – 1
Answer
		
(-2, -15)
		
(2, 69)
		
(1, 27)
		
(-3/2, -67/4)

anonymous · Answer

please someone help me

anonymous · Answer

is it the last one

anonymous · Answer

here u can see http://www.wolframalpha.com/input/?i=find+vertex+of+y+%3D+7x2+%2B+21x+%E2%80%93+1

anonymous · Answer

no problem u can put many questions

anonymous · Answer

Shakir can you stop it now ??

anonymous · Answer

@best.shakir everytime you are giving links..

anonymous · Answer

ok sorry

anonymous · Answer

@waterineyes u can explain

anonymous · Answer

i dont know to explain so that i sent links

anonymous · Answer

Yes if you give me a chance before posting the direct answer links..

anonymous · Answer

Here, we have an quadratic equation:

$$y = 7x^2 + 21x - 1$$

Here:

a = 7, b = 21 and c = -1:

Vertex is given by:

$$Vertex(h,k) = (\frac{-b}{2a}, \frac{-D}{4a})$$

anonymous · Answer

$$h = \frac{-21}{14} \implies h = \frac{-3}{2}$$

anonymous · Answer

Now find Discriminant:

$D = b^2 - 4ac = 469$

$$k = \frac{-469}{28} = \frac{-67}{4}$$

anonymous · Answer

$$(h,k) = (\frac{-3}{2}, \frac{-67}{4})$$

anonymous · Answer

Getting @best.shakir

anonymous · Answer

yep......