Maths trignometry

Question

If tan A = 12/5 (fraction) and A is acute, find the value of 5sinA - cosA/12sinA-13cosA

Answer 1

(5sinA - cosA)/(12sinA - 13cosA) = (5tanA - 1)/(12tanA - 13) = (5·12/5 - 1)/(12·12/5 - 13) = 11/(144/5 - 13) =

= 55/(144 - 65) = 55/79

Answer 2

It's a 5-12-13 right triangle with hypotenuse =13

sinA =12/13

cosA = 5/13

5sinA = 60/13

12sinA = 144/13

13cosA = 65/13

5sinA-cosA/12sinA -13cosA = 60/13 - 5/144 - 65/13 = -5/13 -5/144 = -720/1872- -9360/1872 =- 10080/1872 =about 5.4

UNLESS you really meant (5sinA-cosA)/(12sinA-13cosA)

then

(60/13 -5/13)/(144/13-65/13) = (55/13)/(79/13 = 55/79

Odds are you want 55/79