• Course • Mathematics I (MAT1581)
• Institution • University Of South Africa (Unisa)
MAT1581 Assignment 3 Memo | Due 5 August 2025. Step by Step Calculations
Provided.
Question 1: 6 Marks Determine the following limits: (1.1) lim (3) x→−1 x3 − 2 x4 + 4x −
3 (1.2) lim (3) x→3 x3 − 8 x2 − 4
1.1 lim →→ − 1 𝑥 3 − 2 𝑥 4 + 4 𝑥 − 3 x→ −1 lim
x 4 +4x−3 x 3 −2
Step 1: Substitute 𝑥
− 1 x=−1.
Numerator: ( − 1 ) 3 − 2
−1−2
− 3 Numerator: (−1) 3 −2=−1−2=−3 Denominator: ( −
1)4+4(−1)−3
1−4−3
− 6 Denominator: (−1) 4 +4(−1)−3=1−4−3=−6 Step 2: Simplify.
−3−6
1 2 −6 −3
21
, Answer:
lim 𝑥 → − 1 𝑥 3 − 2 𝑥 4 + 4 𝑥 − 3
1 2 x→−1 lim
x 4 +4x−3 x 3 −2
21
1.2 lim 𝑥 → 3 𝑥 3 − 8 𝑥 2 − 4 x→3 lim
x 2 −4 x 3 −8
Step 1: Substitute 𝑥
3 x=3.
Numerator: 3 3 − 8
27 − 8
19 Numerator: 3 3 −8=27−8=19 Denominator: 3 2 −
4
9−4
5 Denominator: 3 2 −4=9−4=5 Step 2: Simplify.
19 5 5 19
Answer: