Question

HELP FAST PLEASE!!

If 2tan^2x-secx=1, which of the following are true? select all that apply.
secx=-1
secx=3
tanx=3
tanx=-1
secx=3/2

Answer 1

I think it is B. and C.
secx = 3 and tanx = 3
Hope it helps

Answer 2

Option A and E are true.

Explanation:

If
`2tan^(2)x-secx=1` is the equation then the equation can be further solved as

`2[(sec^(2)x-1)]-secx=1`

`2sec^(2)x-secx=3`

Now we further check the equation whether true for the given options.

For sec = -1

2(-1)²-(-1) = 3

So true for this value.

For secx = 3

2(3)²-3 = 18-3 = 15

So for secx = 3 equation is not true

For sec x = 3/2

2(3/2)²-3/2 = 2×(9/4)-3/2 =(9/2)-3/2 = 3

So true for the given value

For tax = 3

Further the equation can be written as

`2tan^(2)x-\sqrt{1+tan^(2)x} =1`

2(3)²-√(1+3²)=18-√10

So for tanx = 3 equation is not true

For tanx = -1

`2tan^(2)x-\sqrt{1+tan^(2)x}`

2(-1)²-√1+(-1)² = 2-√2

So for tax = -1 is not true.

Therefore option A and E are true.