I would say it’s the first one because if you round it it is going to be approximately 12 so that is my reason and also why it isn’t number two is because if you subtract 13.26 and 7.98 you get 5. Something so that’s why
The discount is $1.19 unless you have to round up than it is $1.20. in order to solve this problem you would set up a proportion. So your proportion would be x over 7.99 = 15 over 100. Than you would cross multiply. 7.99*15=119.85. and 100*x=100x. than u divided both sides by a 100. than x= 1.19. which 1.19 is the discount.
First we solve this equation:
x = cos^-1(0) = pi/2 and 3pi/2
Now, this is the answer for angles between 0 and 2pi
but there are "negative angles" and angles larger than 2pi
so the general solution that includes all of these cases is:
x = pi/2 + n*pi
here n is any integer.
Is that just the question? I can help you out but it doesn’t make any sense.