Question

Please help

Trig: Laws of Cosines.
In Δ FTP , side t =5, side p =7 and m < F= 175* . Find side ' f' to the nearest integer.

Answer 1

Answer: 12

Explanation:

law of cosines states that f^2 = t^2 + p^2 - 2tp cos(F)

so f^2 = 5^2 + 7^2 - 2*5*7*cos(175)

f^2 = 74 - (-69.7336)

f^2 = 143.7336

f = 11.9889

which rounds to 12

Answer 2

f = 11.946

f = 12 (Appropriately)

Explanation:

Cosine Rules states that:

Cos F = (p² + t² - f²) / 2pt

f²= p² + t² - 2pt CosF

PARAMETERS from the Question:

f = ??

p = 7

t = 5

F = 175°

Therefore:

f²= p² + t² - 2pt CosF

f² = 7² + 5² - 2 * 7 * 5 Cos 175°

f² = 48 + 25 - 70 Cos 175°

f² = 73 - (70 * - 0.996)

f² = 73 + 69.72

f² = 142.72

f = √142.72

f = 11.946

f = 12 (Appropriately)

Math is Fun Really