188k views
4 votes
Please help me figure out this trig identities problem where the short leg = 3 and the long leg =
√(x^2-9). Theta is located between the hypotenuse and the short leg.

(a) Find sec() and write this as an equation.

(b) Solve the equation from part (a) for .

(c) Solve the equation from part (a) for .

(d) Express
√(x^2-9) in terms of , simplifying as much as possible.

Please help me figure out this trig identities problem where the short leg = 3 and-example-1
User Roy Shmuli
by
7.4k points

1 Answer

2 votes

Answer: the solutions for the given trig identities problem are:

(a) sec(θ) = / 3

(b) θ = sec^(-1)(/3)

(c) θ = cos^(-1)(3 / )

(d) θ = cos^(-1)(sqrt(1 - 9/))

Step-by-step explanation: To solve this trigonometry problem, we are given the short leg as 3 and the long leg as . Let's find the values of the trigonometric functions using these given lengths.

(a) To find sec(θ), we need to use the definition of secant:

sec(θ) = hypotenuse / adjacent

In this case, the hypotenuse is the long leg, and the adjacent side is the short leg.

Therefore, sec(θ) = / 3

(b) To solve the equation for θ, we can take the inverse secant of both sides:

sec(θ) = / 3

θ = sec^(-1)(/3)

(c) To solve the equation for θ, we can use the reciprocal identity of secant:

sec(θ) = 1 / cos(θ)

1 / cos(θ) = / 3

cos(θ) = 3 /

θ = cos^(-1)(3 / )

(d) To express θ in terms of , we can use the Pythagorean identity:

sin^2(θ) + cos^2(θ) = 1

Since we know the short leg is 3, we can substitute sin(θ) = 3 / hypotenuse:

(3 / )^2 + cos^2(θ) = 1

9/ + cos^2(θ) = 1

cos^2(θ) = 1 - 9/

cos(θ) = sqrt(1 - 9/)

θ = cos^(-1)(sqrt(1 - 9/))

User Starsinmypockets
by
7.2k points