Given that tan^2 e= 3/8 what is the value of sec e? a. +√8/3 b.+ √11/8 c. 11/8 d. 8/3

ANSWER

EXPLANATION

We use the Pythagorean Identity,

It was given that,

We substitute the values into the identity to obtain,

We take square root of both sides to get,

sec e = √(11/8) ⇒ answer B

Step-by-step explanation:

* Lets revise some identities in trigonometry

# sin²x + cos²x = 1

- Divide both sides by cos²x

∴ sin²x/cos²x + cos²x/cos²x = 1/cos²x

∵ sinx/cosx = tanx

∴ sin²x/cos²x = tan²x

∵ cos²x/cos²x = 1

∵ 1/cosx = secx

∴ 1/cos²x = sec²x

* Now lets write the new identity

# tan²x + 1 = sec²x

- Let x = e

∴ tan²e + 1 = sec²e

- Substitute the value of tan²e in the identity

∵ tan²e = 3/8

∴ 3/8 + 1 = sec²e

- Change the 1 to the fraction 8/8

∴ 3/8 + 8/8 = sec²e ⇒ add the fractions

∴ 11/8 = sec²e

- Take square root for the two sides to find sec e

∴ sec e = √(11/8)

∴ The answer is B

b.an increase in a causes b to decrease