SDMAT04
Jan/Feb 2021
UNIVERSITY EXAMINATIONS
January / February 2021
SDMAT04
100 Marks
Duration: .2 Hours
This paper consists of (6) pages.
Answer all the Questions
Instructions:
• Read the questions carefully.
• Open book examination – Study material permissible
• It is in your own interest to write legibly and to present your work neatly.
• Use of a non-programmable pocket calculator is allowed.
• All working details must be shown.
• Number your answers exactly as the questions are numbered.
• Please start your answer to each question on a new page.
• Please write legibly and present your work neatly.
To upload the examination, login to myUnisa click on “myAdmin”,” Assessment
Admin”and then on “Examination submission”. Choose the module you want to submit.
Remember to click “Submit “once you have finished uploading your examination answer
script.
1
[TURN OVER]
Open Rubric
, SDMAT04
Jan/Feb 2021
Question 1
1.1
The graph of a cubic function f is sketched below.
The equation of the curve is given as 𝑓(𝑥) = −𝑥3 + 𝑏𝑥2 + 𝑐𝑥 −where 𝑏 𝑎𝑛𝑑 𝑐 are
1
constants. If 𝑓(1) = 4, and 𝑓 // ( = 1
2
1.1.1 Find the values of a 𝑎𝑛𝑑 𝑏.
the value of a =-1
to fimd the value of b and c first subtitude f(1)=4 in to original equation
4= -(1)3 +b(1)2 +c(1)
4=-1+b+c………….equation 1
Then find second derivatives meaning
f //(x) =-6x+2b+0 ………..equation 2
Solve for b from equation 2 by substituting f’’(1/2)=1
1=-6(1/2)+2b
1=-3+2b
4=2b
b=2
from equation 1 substitute value of b=2
4=-1+2+c
C=3
(3)
2
[TURN OVER]
Jan/Feb 2021
UNIVERSITY EXAMINATIONS
January / February 2021
SDMAT04
100 Marks
Duration: .2 Hours
This paper consists of (6) pages.
Answer all the Questions
Instructions:
• Read the questions carefully.
• Open book examination – Study material permissible
• It is in your own interest to write legibly and to present your work neatly.
• Use of a non-programmable pocket calculator is allowed.
• All working details must be shown.
• Number your answers exactly as the questions are numbered.
• Please start your answer to each question on a new page.
• Please write legibly and present your work neatly.
To upload the examination, login to myUnisa click on “myAdmin”,” Assessment
Admin”and then on “Examination submission”. Choose the module you want to submit.
Remember to click “Submit “once you have finished uploading your examination answer
script.
1
[TURN OVER]
Open Rubric
, SDMAT04
Jan/Feb 2021
Question 1
1.1
The graph of a cubic function f is sketched below.
The equation of the curve is given as 𝑓(𝑥) = −𝑥3 + 𝑏𝑥2 + 𝑐𝑥 −where 𝑏 𝑎𝑛𝑑 𝑐 are
1
constants. If 𝑓(1) = 4, and 𝑓 // ( = 1
2
1.1.1 Find the values of a 𝑎𝑛𝑑 𝑏.
the value of a =-1
to fimd the value of b and c first subtitude f(1)=4 in to original equation
4= -(1)3 +b(1)2 +c(1)
4=-1+b+c………….equation 1
Then find second derivatives meaning
f //(x) =-6x+2b+0 ………..equation 2
Solve for b from equation 2 by substituting f’’(1/2)=1
1=-6(1/2)+2b
1=-3+2b
4=2b
b=2
from equation 1 substitute value of b=2
4=-1+2+c
C=3
(3)
2
[TURN OVER]
