Maths a level graphs

Hey, how do I plot an equation/ curve with an unknown constant. I’ve noticed lots in exam qs ask this and I’m struggling.
E.g this Q

I get this Q but there’s much harder qs is there any way/ method or a YouTube evidence that can help me out. I’m really stressed plz help

(edited 1 year ago)

Reply 1

tonyiptony

Let's say you don't know what the k is. From the fact that the equation has two distinct positive roots, can you at least mark down some points of interest?
Also, do you know what the curve is supposed to look like, without the constraint of the axes? Then you can kind of "fit" the curve into the axes.

Curve sketching is nothing more than (i) finding points/asymptotes of interest; then (ii) recognize what the curve should roughly look like, then (iii) fit it in. That said, (ii) is often the trickiest as you do need to know your standard functions.

(edited 1 year ago)

Reply 2

Muttley79

Original post by Alevelhelp.1

Hey, how do I plot an equation/ curve with an unknown constant. I’ve noticed lots in exam qs ask this and I’m struggling.
E.g this Q
I get this Q but there’s much harder qs is there any way/ method or a YouTube evidence that can help me out. I’m really stressed plz help

It's a sketch they want not an accurate graph. What does the phrase 'two disctinct positive roots' tell you about where the graph cuts the x-axis? What shape is this graph?