Triangle ABC is right-angled at C, then cos(A+B)= ?
Options are-
a. 0
b. 1
c. 1/2
d. (root3)/2

Asked by Sthitaprajna Mishra | 28th Aug, 2014, 10:47: PM

Expert Answer:

i n space T r i a n g l e space A B C comma space C equals 90 s o space A plus B equals 180 minus C equals 180 minus 90 equals 90  C o s space 90 space equals space 0

Answered by Dharma Teja | 30th Aug, 2014, 01:15: AM