Math, asked by parthasarathia7, 14 days ago

3. The magnitude of vectors A, B and C are 3, 4 and 5 units respectively. If Ä+B = 7, then the angle between A and B is​

Answers

Answered by jeon36491
9

Answer:

Squaring the given equation on both sides

Let θ be the angle between

A

and

B

A

+

B

=

C

Squaring on both sides

(

A

+

B

)

2

=(

C

)

2

⇒∣

A

2

+∣

B

2

+2

A

.

B

=∣

C

2

⇒∣

A

2

+∣

B

2

+2∣

A

∣∣

B

∣cosθ=∣

C

2

....(1)

Step 2: Calculations

Put the values of all the variables in eq (1) to get θ

(3)

2

+(4)

2

+2×3×4cosθ=(5)

2

⇒ cosθ=0

⇒ θ=90

Answered by kamaljeetsingh1930
0

Step-by-step explanation:

Squaring the given equation on both sides

Let θ be the angle between

A and B

A + B = C

Squaring on both sides

( A + B ) ^2 =( C ) ^2

⇒∣ A ∣ ^2 +∣ B ∣^ 2 +2 A . B =∣ C ∣ ^2

⇒∣ A ∣^ 2 + ∣ B ∣^ 2 +2 ∣A∣∣B∣ cos θ=∣ C ∣ ^2

....(1)

Step 2: Calculations

Put the values of all the variables in eq (1) to get θ

(3) ^2 +(4)^2+2×3×4cosθ=(5) ^2

⇒ cosθ=0

⇒ θ=90∘

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