4. Evaluate [tex]Z = 4y^2 + x^2[/tex] given that [tex]y = 2\tan(t)[/tex] and [tex]x = \frac{4}{\sqrt{8 - q^2}}[/tex] at [tex]t = \frac{\pi}{3}[/tex] and [tex]q = 2.5[/tex], correct to 4 decimal places.



Answer :

To evaluate [tex]\( Z = 4y^2 + x^2 \)[/tex] with the given conditions [tex]\( y = 2 \tan t \)[/tex] and [tex]\( x = \frac{4}{\sqrt{8 - q^2}} \)[/tex] at [tex]\( t = \frac{\pi}{3} \)[/tex] and [tex]\( q = 2.5 \)[/tex], we need to follow these steps:

1. Calculate [tex]\( y \)[/tex]:
Given [tex]\( y = 2 \tan t \)[/tex] and [tex]\( t = \frac{\pi}{3} \)[/tex],
[tex]\[ y = 2 \tan \left(\frac{\pi}{3}\right) \][/tex]
We know that [tex]\( \tan \left(\frac{\pi}{3}\right) = \sqrt{3} \)[/tex], so:
[tex]\[ y = 2 \cdot \sqrt{3} = 2\sqrt{3} \][/tex]
When rounded to 4 decimal places:
[tex]\[ y \approx 3.4641 \][/tex]

2. Calculate [tex]\( x \)[/tex]:
Given [tex]\( x = \frac{4}{\sqrt{8 - q^2}} \)[/tex] and [tex]\( q = 2.5 \)[/tex],
[tex]\[ x = \frac{4}{\sqrt{8 - (2.5)^2}} \][/tex]
First, compute [tex]\( (2.5)^2 \)[/tex]:
[tex]\[ (2.5)^2 = 6.25 \][/tex]
Then,
[tex]\[ 8 - 6.25 = 1.75 \][/tex]
Now,
[tex]\[ x = \frac{4}{\sqrt{1.75}} \][/tex]
When rounded to 4 decimal places:
[tex]\[ x \approx 3.0237 \][/tex]

3. Compute [tex]\( Z \)[/tex]:
Given [tex]\( Z = 4y^2 + x^2 \)[/tex],
Substitute the computed values for [tex]\( y \)[/tex] and [tex]\( x \)[/tex]:
[tex]\[ y \approx 3.4641 \quad \text{and} \quad x \approx 3.0237 \][/tex]
Then,
[tex]\[ Z = 4y^2 + x^2 \][/tex]
Compute [tex]\( 4y^2 \)[/tex]:
[tex]\[ 4 \times (3.4641)^2 \approx 48.0001 \][/tex]
Compute [tex]\( x^2 \)[/tex]:
[tex]\[ (3.0237)^2 \approx 9.1428 \][/tex]
Add these results together:
[tex]\[ Z \approx 48.0001 + 9.1428 = 57.1429 \][/tex]

Thus, the evaluated value of [tex]\( Z \)[/tex] correct to 4 decimal places is:
[tex]\[ Z \approx 57.1429 \][/tex]

Therefore, the final results are:
[tex]\[ y \approx 3.4641, \quad x \approx 3.0237, \quad \text{and} \quad Z \approx 57.1429 \][/tex]