• Congratulations to the Class of 2024 on your results!
    Let us know how you went here
    Got a question about your uni preferences? Ask us here

functions (1 Viewer)

purpletree

New Member
Joined
Mar 30, 2012
Messages
13
Gender
Female
HSC
2012
determine for what value of c the equation |2x-1|=x+c has exactly two solutions
 

Manroop

Member
Joined
Feb 17, 2009
Messages
63
Gender
Undisclosed
HSC
2011
solve the equation and you should get two equation involving x and c. Solve simultaneously to get value of c.
 

Carrotsticks

Retired
Joined
Jun 29, 2009
Messages
9,494
Gender
Undisclosed
HSC
N/A
Just do it graphically.

By drawing the sketch of y=|2x-1| and y=x-0.5, we see that it intersects only once (at the bottom of the 'V') so quite clearly any larger values of C than -0.5 will yield two points of intersections...

Alternatively, you could square both sides, make a quadratic in terms of X, then let the discriminant be > 0.

You will easily see that the region is c > -0.5.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top