It may sound straightforward, but just take each line at a time and it makes it much easier. After drawing a Cartesian plane, map out your intercepts (if there are any), put a dotted line for any boundaries which exist (so for part c, there is a boundary at x = 1 where the derivative changes around this point). I'd advise to use a dotted line first before drawing over it in solid pen, so you don't make a mistake
A)
(1,0) and (-3,0) are x-intercepts
At x= -1 there is a stationary point, could possibly be a point of inflection
The last two lines prove that it is a maximum stationary point
• (for x<-1 it is a positive gradient, therefore a positive curve / )
• (for x>-1 it is a negative gradient, therefore a negative curve \ )
/-\
C)
It is an odd function therefore -f(-x) = f(x)
For example:
f(-2) = -4 ---> ∴ -f(-2) = 4
f(2) = 4
∴ -f(-2) = f(2)
[If f(2) is in the 1st quadrant then-f(-2) will be in the 3rd quadrant)
(3,0) ---> x-intercept at x=3
Stationary point at x=1
Gradient is positive for x>1
Gradient is negative for x<1
∴ x=1 is a minimum point (this doesn't make sense when trying to draw the graph, but from observing the info given, it is a min point, i might be wrong but maybe the question is flawed, try having a look at the answers if you can)
Due to the domain of 0 ≤ x < 1
there will be a point of inflection at x = 0 as the concavity changes
b)
function is above the x axis the whole time
there is a stationary point at x = 0
the function is decreasing for negative values of x
function is increasing for positive values
c)
function is reflected over the x axis
x intercept at x = 3
stationary point at x = 1
function is increasing for values of x greater than 1
function is decreasing for values less than x
and then you can just deduce the function as how cosine did. Ideally you should read the statements in your head but if its confusing at first, just write it down on paper.