Question

simplify the flowing expression by applying the odd/even identities, cofunctiom identities, and cosin of a sum or difference identities.

Answer 1

cos(14)cos(16)+sin(-14)cos(74)

Answer 2

this is the subtraction angle formula for cosine

Answer 3

no, that was wrong sorry

Answer 4

\[\sin(-14)=-\sin(14)\] so this is the same as \[\cos(14)\cos(16)-\sin(-4)\cos(74)
\]

Answer 5

so it is the ADDITION angle formula for cosine

Answer 6

add \(16+74\) then find the cosine of that number

Answer 7

pic of a triangle like below may help...