h2 graphing technique

absol SG

hi, regarding (iv) of this question, how do you know that the max turning point must occur between x=a and x=b(from the solutions)? because i did the other way round(thought its arbitrary) but putting min turning point between x=a and x=b, but i wonder if there is really a way to determine.

btw this solution is scanned from the purple book contained worked soln to h2 maths a lvl qns by mr wee...lol.

sry for e images in wrong order, no idea how to remove the first one and put it below....

wee_ws SG

Hi,

There is an x-intercept at x = a and another x-intercept at x = b. By the shape of the graph (increasing around the region x = a and decreasing around the region near x = b), there has to be a maximum turning point in between.

Also, I mentioned that one could use specific values (which must be all positive) to determine the shape of the graph, because it is never easy to see the behaviour with arbitrary values of a, b and c.

Thanks!

Cheers,
Wen Shih