How do you find the axis of symmetry, graph and find the maximum or minimum value of the function y = 2x^2 - 4x -3y=2x24x3?

1 Answer

Axis of symmetrycolor(blue)(" "x=1) x=1
Minimum value of the function color(blue)(=-5)=5
See the explanation for the graph

Explanation:

The solution:

To find the Axis of symmetry you need to solve for the Vertex (h, k)(h,k)

Formula for the vertex:
h=(-b)/(2a)h=b2a and k=c-b^2/(4a)k=cb24a

From the given y=2x^2-4x-3y=2x24x3
a=2a=2 and b=-4b=4 and c=-3c=3

h=(-b)/(2a)=(-(-4))/(2(2))=1h=b2a=(4)2(2)=1
k=c-b^2/(4a)=-3-(-4)^2/(4(2))=-5k=cb24a=3(4)24(2)=5

Axis of symmetry:

x=hx=h

color(blue)(x=1)x=1

Since aa is positive, the function has a Minimum value and does not have a Maximum.

Minimum value color(blue)(=k=-5)=k=5

The graph of y=2x^2-4x-3y=2x24x3
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To draw the graph of y=2x^2-4x-3y=2x24x3, use the vertex (h, k)=(1, -5)(h,k)=(1,5) and the intercepts.

When x=0x=0,
y=2x^2-4x-3y=2x24x3
y=2(0)^2-4(0)-3=-3" "y=2(0)24(0)3=3 means there is a point at (0, -3)(0,3)

and when y=0y=0,
y=2x^2-4x-3y=2x24x3
0=2x^2-4x-30=2x24x3

x=(-b+-sqrt(b^2-4ac))/(2a)=(-(-4)+-sqrt((-4)^2-4(2)(-3)))/(2(2))x=b±b24ac2a=(4)±(4)24(2)(3)2(2)

x=(+4+-sqrt(16+24))/(4)x=+4±16+244

x=(+4+-sqrt(40))/(4)x=+4±404

x=(+4+-2sqrt(10))/(4)x=+4±2104

x_1=1+1/2sqrt(10)x1=1+1210

x_2=1-1/2sqrt(10)x2=11210

We have two points at (1+1/2sqrt(10), 0)(1+1210,0) and (1-1/2sqrt(10), 0)(11210,0)

God bless...I hope the explanation is useful.