to get the secnond primciple value do you not do 180- the first principle value you get?? e.g 180 - ( -0.928) rather than finding at 2pi? in the first q
So it depends on what the question is asking for and what the equation is. If the question is asking about a maximum, we will probably want cos to be at its maximum, which is 1. If the question is asking about a minimum, we will probably want cos to be at its minimum, which is -1. However, there are exceptions to it. For example, in Qbii at the end of the video (38:32 timestamp), we want the maximum of the equation. However, because the cos has a negative sign in front of it (- root 109 cos(80t + 16.70)), in order to get the maximum, we actually want to minimise cos. This is because of the negative sign at the front. So we say that cos is the minimum value of -1.
Amazing Video, helped me so much!
Ah thank you so much!
to get the secnond primciple value do you not do 180- the first principle value you get?? e.g 180 - ( -0.928) rather than finding at 2pi? in the first q
No, I think you’re getting confused with how we solve certain trigonometric equations
why is it somertimes 1 and sometimes -1?? even tho its both cos
I don’t understand what you’re asking, is it for one of the questions in the video?
@@formergcseandalevelstudentsometimes the maximum is 1 and sometimes it’s -1, different questions keep saying different things , doing my head in
Even tho it’s all cos
So it depends on what the question is asking for and what the equation is. If the question is asking about a maximum, we will probably want cos to be at its maximum, which is 1. If the question is asking about a minimum, we will probably want cos to be at its minimum, which is -1.
However, there are exceptions to it. For example, in Qbii at the end of the video (38:32 timestamp), we want the maximum of the equation. However, because the cos has a negative sign in front of it (- root 109 cos(80t + 16.70)), in order to get the maximum, we actually want to minimise cos. This is because of the negative sign at the front. So we say that cos is the minimum value of -1.
@@formergcseandalevelstudent i fucking love you tysm