Trigonometry Question (1 Viewer)

[sheroom]

Hi everyone,

After much frustration, I have resulted to this forum to answer my question! It is 15)c) in the picture below.



Thanks in advance!

EDIT: I should have added I can get the obvious results of 30 and -150, but the answers say that it is also 0 and +-180

 

[InteGrand]

Hi everyone,

After much frustration, I have resulted to this forum to answer my question! It is 15)c) in the picture below.

View attachment 32770

Thanks in advance!

EDIT: I should have added I can get the obvious results of 30 and -150, but the answers say that it is also 0 and +-180

Remember to include the case of tan x = 0 (if we divide through by tan x in the equation, we are ignoring the possibility of tan x = 0). When tan x = 0, the equation is also satisfied, and this gives us the solutions you missed.

 

[Paradoxica]

 

[sheroom]

Ah, OK - so that's the process? When writing my working, I should remember that if dividing through by tan x, then I need to remember to account for tan x = 0... Thanks!

 

[InteGrand]

Ah, OK - so that's the process? When writing my working, I should remember that if dividing through by tan x, then I need to remember to account for tan x = 0... Thanks!

Yeah. That's because we can't divide by 0, so we need to deal with this case separately. Welcome!

 

[Paradoxica]

Yeah. That's because we can't divide by 0, so we need to deal with this case separately. Welcome!

what about tanx = infinity?

 

[KingOfActing]

what about tanx = infinity?

Think about the question as asking about the zeros of . At , the graph of the function clearly doesn't cross the x-axis.