Question

if tan alpha =5/12,find the value of sec alpha

Answer 1

tan alpha = perpendicular/base so here P=5,B=12 using pgt to find H(hypotenuse) H square=B square+ P square, H square =12square+5squre, Hsquare=144+25=Hsquare=169 H=13, so sec =H/P=13/5. don't forget to say thanks.

Answer 2

Answer:

13/12

Step-by-step explanation:

We need to write down how tan relates to sec.

Sec theta = 1/ cos theta

Now Tan theta = Sin theta / Cos theta

From this relationship we can get Cos theta as follows :

Cos theta = Sin theta / Tan theta

1/ Cos theta = Tan theta / Cos Theta

That implies :

Sec theta = Tan theta/Sin theta

Tan alpha = 5/12

And Tan = opposite / Adjacent

Hence the sides of the right angled triangle are 5, 12 and c

By Pythagoras theorem we can get c.

5^2 + 12^2 = 169

c = square root of 169 = 13

Cos = adjacent / hypotenuse

Adjacent = 12

Hypotenuse = 13

Cos alpha = 12/13

Sec = 1/Cos

= 13/12