How do I find 2 tan squared time x = sec times x -1

To solve the equation 2tan^2(x) = sec(x) - 1, let's break down the steps:

Step 1: Start by using the fundamentals of trigonometric identities and equations. Recall that tan(x) can be expressed as sin(x) / cos(x) and sec(x) can be expressed as 1 / cos(x).

Step 2: Rewrite the equation in terms of sin(x) and cos(x):

2(sin^2(x) / cos^2(x)) = 1 / cos(x) - 1

Step 3: Simplify the equation by multiplying both sides by cos^2(x) to eliminate the denominators:

2sin^2(x) = 1 - cos(x)

Step 4: Use the identity sin^2(x) + cos^2(x) = 1 to replace sin^2(x) in the equation:

2(1 - cos^2(x)) = 1 - cos(x)

Step 5: Distribute and simplify:

2 - 2cos^2(x) = 1 - cos(x)

Step 6: Rearrange the equation to bring all terms to one side:

2cos^2(x) - cos(x) - 1 = 0

Step 7: Now, this is a quadratic equation in terms of cos(x). We can solve it by factoring, completing the square, or using the quadratic formula.

In this case, the quadratic equation is factorable:

(2cos(x) + 1)(cos(x) - 1) = 0

Step 8: Set each factor to zero and solve for cos(x):

2cos(x) + 1 = 0 --> cos(x) = -1/2
cos(x) - 1 = 0 --> cos(x) = 1

Step 9: Find the solutions for x by using the inverse cosine function (also known as arccosine):

cos(x) = -1/2 --> x = arccos(-1/2)
cos(x) = 1 --> x = arccos(1)

Step 10: Lastly, find all possible solutions for x by considering the domain of the inverse cosine function, which is restricted to x ∈ [0, π].

Therefore, x can take the values:

x = arccos(-1/2) (if it falls within the valid domain)
x = arccos(1)

Note: Remember to convert the inverse cosine values to degrees or radians, depending on the context or specific instructions given.