Gr. 12 Advanced Functions - 5.3 Applications of Trig Functions

[netrickal]

for the second question, I think that since the temperature is at its max after 9 hours, it means that 8 hours or two cycles ago (1am), the temperature was also at its max. Since 1am is 1 hour after midnight, I can assume that the cosine function has been shifted 1 hour to the right which makes 1 a possible value for d. So I think that t(h)=5cos(pi/2(h-1))+71 would also work? Is the thinking correct? Someone fact check please 🙏

[voidz]

For the last question what is the equivalent sin function. Can u please walk me through?