In Δ ABC, ∠A= 90°, AB = 20 cm and BC = 29 cm. What is the value of (sinB - cotC)?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. -(189/580).
In traingle ABC,
292 = 202 + AC2
841 - 400 = AC2
AC = 21
(sinB - cotC) = 21/29 - 21/20
= (420 - 609)/580
= -189/580