Question

For this right triangle determine cos(90-theta)

Answer 1

have you covered the sum/difference trigonometric identities yet?

Answer 2

nope im in algebra 2

Answer 3

well let's take a look at the triangle
recall that all internal angles in a right triangle add up to 180 degrees

so that means \(\bf \theta+{\color{brown}{ \beta}}+90=180\implies \theta+{\color{brown}{ \beta}}=90\implies {\color{brown}{ \beta}}=90-\theta\qquad thus
\\ \quad \\
cos(90-\theta) \iff cos({\color{brown}{ \beta}})\to \cfrac{adjacent\ side}{hypotenuse}\to \cfrac{a}{c}\)

Answer 4

hmmm actaully the adjacent is "b" one sec... so