SOAL TENTANG TRIGONOMETRI ANALITIKA. MOHON BANTUANNYA. BESOK DIKUMPULKAN

jawab

A tumpul
B lancip

cos A = -12/13  --> misal x/r
y= √(r²- x²)
y = √(13²-12²)
y = 5
sin A = y/r= 5/13

tanB = 8/15 -->misal = y/x
r = √(x²+y²) = √(15² +8²)
r= 17
sin B = y/r = 8/17
cos B = x/r = 15/17

sin (A + B) =  sin A cos B + cos A sin B

= (5/13)(15/17) +  (-12/13)(8/17)

=   75/221 - 96 /221

= - 21/221