Figure 1 shows part of the curve with equation $y = f(x)$, $x \\in \\mathbb{R}$ - Edexcel - A-Level Maths Pure - Question 24 - 2013 - Paper 1
Question 24
Figure 1 shows part of the curve with equation $y = f(x)$, $x \\in \\mathbb{R}$.
The curve passes through the points $Q(0,2)$ and $P(-3,0)$ as shown.
(a) Find t... show full transcript
Worked Solution & Example Answer:Figure 1 shows part of the curve with equation $y = f(x)$, $x \\in \\mathbb{R}$ - Edexcel - A-Level Maths Pure - Question 24 - 2013 - Paper 1
Step 1
Find the value of $f(-3)$
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
To find f(−3), we reference the points on the curve. Since the point P(−3,0) lies on the curve, it indicates that when x=−3, the value of y=f(−3)=0. Thus, we conclude:
f(−3)=0
Step 2
Sketch the curve with equation $y = f^{+}(x)$
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The function f+(x) represents the positive part of f(x). The sketch of this function presents a graph where any negative values of f(x) are replaced by zero. The important points to mark are (0,2) and (2,0). The curve should be drawn in such a way that it remains in the positive region above the x-axis, reflecting any negative parts to the x-axis.
Step 3
Sketch the curve with equation $y = f(|x|) - 2$
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Here, f(∣x∣) reflects the function about the y-axis due to the absolute value. By subtracting 2, the graph is shifted down by 2 units. Key points to note are (0,0) for f(0)−2 and (2,0) reflects to (−2,0) as well. The curves should mirror each other across the y-axis.
Step 4
Sketch the curve with equation $y = 2f\left(\frac{1}{2}x\right)$
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
This transformation stretches the graph vertically by a factor of 2 and horizontally by a factor of 2. Thus, points that were originally (x,y) will transform to (2x,2y). The coordinates to highlight are at (−6,0) and (0,0). The result will show the curve with a wider base and stretched upwards.