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egracer
 one year ago
The equation f(x) = 5x2 − 30x + 6 represents a parabola. What is the vertex of the parabola?
(−5, 281)
(5, −19)
(−3, 141)
(3, −39)
egracer
 one year ago
The equation f(x) = 5x2 − 30x + 6 represents a parabola. What is the vertex of the parabola? (−5, 281) (5, −19) (−3, 141) (3, −39)

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anonymous
 one year ago
Best ResponseYou've already chosen the best response.0In the general equation of a parabola\[f \left( x \right) = ax ^{2} + bx + c\]The xcoordinate of the vertex is given by\[x=\frac{ b }{ 2a }\]Then calculate f(x) using this value of x to give you the ycoordinate of the vertex.

egracer
 one year ago
Best ResponseYou've already chosen the best response.0Sorry trying to figure this out haha math isn't my best subject so its a little harder let me try to recalculate

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0No problem. Take your time. What do you get for the xcoordinate? (b/2a)

egracer
 one year ago
Best ResponseYou've already chosen the best response.0would the x coordinate be 39/2a?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Not quite. From looking at the given quadratic, what is the value of a and the value of b?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0a multiplies x^2 and b multiplies the x

egracer
 one year ago
Best ResponseYou've already chosen the best response.0honestly I have no clue I'm so confused on how to do this could you explain like in details like how to solve it

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I just did. But let's back up. The given quadratic function is\[f \left( x \right) = 5x ^{2}  30x + 6\]Compare that with\[f \left( x \right) = ax ^{2} + bx + c\]a is the number that multiplies x^2 b is the number that multiplies x What are they?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Perfect. Now the xcoordinate is given by\[x = \frac{ b }{ a }\]Plug in those values of a and b . What do you get?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Sorry. It's\[x=\frac{ b }{ 2a }\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So you're calculating\[x=\frac{ b }{ 2a } = \frac{ 30 }{ 2\left( 5 \right) } = ?\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Nope. What is 2 x 5 ?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Good. That's the denominator. Now, what's 30/10 ?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Good. Finally, what's (3) ?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Excellent. So the xcoordinate of the vertex is 3.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Now, to get the ycoordinate of the vertex, put his value of x into the original function and calculate f(3)\[f \left( x \right)=5x ^{2}30x+6\]\[f \left( 3 \right) = 5\left( 3 \right)^{2}30\left( 3 \right) + 6\]What do you get?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Great. Now what is 5 x 3^2 ?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Good. Now what is 30 x 3 ?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Great. Now to put it all together\[f \left( 3 \right) = 5\left( 3 \right)^{2}  30\left( 3 \right) + 6 = 4590+6 = ?\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Good. Now you have the x and ycoordinates of the vertex. Where is the vertex?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0That's it. Well done.

egracer
 one year ago
Best ResponseYou've already chosen the best response.0thank you so much for being patient with me! and helping me understand!

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0You're welcome. Good luck with your studies.
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