How do you find the domain and range of #y = 2x^2 - 5x#?

1 Answer
Aug 29, 2017

Answer:

Domain: #x in RR or (-oo,oo)# .
Range: # y >= -3.125 or [-3.125 , oo)#

Explanation:

#y=2x^2-5x # . Domain : Any real value of x i.e #x in RR#

Range: #y= 2(x^2-5/2x) =2(x^2-5/2x + (5/4)^2) -2 *25/16#

#y = 2(x-5/4)^2 -25/8 = 2( x-1.25)^2 - 3.125#

Vertex is at # (1.25 , -3.125)# , Range : # y >= -3.125#

Domain: #x in RR or (-oo,oo)#

Range: # y >= -3.125 or [-3.125 , oo)#

graph{2x^2-5x [-10, 10, -5, 5]}