Arithmetic operators in MATLAB - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the + operator do in MATLAB?

The + operator adds two numbers or arrays element-wise.

beginner

How do you perform element-wise multiplication in MATLAB?

Use the .* operator to multiply arrays element-wise.

intermediate

What is the difference between * and .* in MATLAB?

* is matrix multiplication, while .* is element-wise multiplication.

beginner

What operator is used for division in MATLAB?

The / operator performs matrix right division. For element-wise division, use ./.

beginner

How do you calculate the power of a number in MATLAB?

Use the ^ operator for matrix power and .^ for element-wise power.

Which operator performs element-wise addition in MATLAB?

A .*

B +

C ^

D ./

The + operator adds elements one by one.

What does the operator ./ do?

A Element-wise multiplication

B Matrix division

C Matrix multiplication

D Element-wise division

./ divides each element of one array by the corresponding element of another.

How do you perform matrix multiplication in MATLAB?

A *

B ./

C +

D .*

The * operator performs matrix multiplication.

Which operator raises each element of an array to a power individually?

A .^

B .*

C ^

D /

.^ applies power to each element separately.

What is the result of 5 + 3 * 2 in MATLAB?

A 16

B 10

C 11

D 13

Multiplication happens before addition, so 3*2=6, then 5+6=11.

Explain the difference between matrix multiplication and element-wise multiplication in MATLAB.

Think about how you multiply matrices vs. multiplying each number separately.

Describe how to perform division and power operations element-wise in MATLAB.

Look for the dot before the operator for element-wise.

Practice

1. Which arithmetic operator in MATLAB is used to multiply two numbers?

easy

A. +

B. -

C. *

D. ^

Solution

1. Step 1: Identify multiplication operator

   In MATLAB, the symbol * is used to multiply two numbers.

2. Step 2: Confirm other operators

   + is addition, - is subtraction, and ^ is power.

3. Final Answer:

   * -> Option C

4. Quick Check:

   Multiplication = * [OK]

Hint: Remember * means multiply in math and MATLAB [OK]

Common Mistakes:

• Confusing * with + or -
• Using ^ for multiplication
• Forgetting * is needed for multiply

2. Which of the following is the correct MATLAB syntax using the power operator to calculate 5 raised to the power 3?

easy

A. 5^3

B. 5**3

C. power(5,3)

D. 5^^3

Solution

1. Step 1: Identify power operator syntax

   In MATLAB, the caret symbol ^ is used for powers, so 5^3 is correct.

2. Step 2: Check other options

   5**3 and 5^^3 are invalid syntax. power(5,3) is a function but not an operator.

3. Final Answer:

   5^3 -> Option A

4. Quick Check:

   Power operator = ^ [OK]

Hint: Use ^ for powers, not ** or ^^ [OK]

Common Mistakes:

• Using ** like other languages
• Typing ^^ by mistake
• Confusing function with operator

3. What is the output of the following MATLAB code?

a = 10; b = 3; c = a / b;

medium

A. 3.3333

B. 3

C. 7

D. 13

Solution

1. Step 1: Understand division operation

   Variable a is 10, b is 3, so c = a / b divides 10 by 3.

2. Step 2: Calculate division result

   10 divided by 3 equals approximately 3.3333 in MATLAB.

3. Final Answer:

   3.3333 -> Option A

4. Quick Check:

   10 / 3 = 3.3333 [OK]

Hint: Division gives decimal result unless integers used carefully [OK]

Common Mistakes:

• Rounding to 3
• Adding instead of dividing
• Confusing division with subtraction

4. Find the error in this MATLAB expression:

result = 4 + * 5;

medium

A. Wrong operator for addition

B. Missing operand before *

C. Extra semicolon

D. No error

Solution

1. Step 1: Analyze the expression syntax

   The expression 4 + * 5 has two operators + and * without a number between them.

2. Step 2: Identify missing operand

   There should be a number between + and *, but it is missing, causing a syntax error.

3. Final Answer:

   Missing operand before * -> Option B

4. Quick Check:

   Operators need numbers between them [OK]

Hint: Operators must have numbers on both sides [OK]

Common Mistakes:

• Leaving out numbers between operators
• Thinking semicolon causes error
• Using wrong operator symbols

5. You want to calculate the expression (2 + 3) ^ 2 - 4 * 5 in MATLAB. Which code correctly computes this?

hard

A. 2 + (3 ^ 2 - 4) * 5

B. 2 + 3 ^ 2 - 4 * 5

C. (2 + 3) ^ (2 - 4) * 5

D. (2 + 3) ^ 2 - 4 * 5

Solution

1. Step 1: Understand operator precedence and parentheses

   The expression (2 + 3) ^ 2 - 4 * 5 means add 2 and 3 first, then square, then subtract 4 times 5.

2. Step 2: Check each option

   (2 + 3) ^ 2 - 4 * 5 matches the original expression exactly. Others change order or grouping, giving different results.

3. Final Answer:

   (2 + 3) ^ 2 - 4 * 5 -> Option D

4. Quick Check:

   Use parentheses to keep order correct [OK]

Hint: Use parentheses to control math order [OK]

Common Mistakes:

• Ignoring parentheses
• Changing operator order
• Misplacing powers or multiplication