If ΔPQR is right angled at Q, then what is the value of cos(P + R)?
Answer & explanation
Correct answer: option 4
If ΔPQR is right angled at Q
i.e. Q = 90º
So,
P + Q + R = 180º
P + 90º + R = 180º
P + R = 90º
Now,
cos ( P + R )
= cos 90º
= 0
If ΔPQR is right angled at Q, then what is the value of cos(P + R)?
Correct answer: option 4
If ΔPQR is right angled at Q
i.e. Q = 90º
So,
P + Q + R = 180º
P + 90º + R = 180º
P + R = 90º
Now,
cos ( P + R )
= cos 90º
= 0