In a triangle OPQ, right-angled at P, OP = 7 cm and OQ - PQ = 1 cm. Determine the values of sin Q + cos Q.
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. .
We have a right-angled triangle OPQ, with the right angle at P.
OP = 7 cm
OQ - PQ = 1 cm
⇒ OQ = 1 + PQ
In a right-angled triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides.
So, OQ2 = OP2 + PQ2
⇒ (1 + PQ)2 = 72 + PQ2
⇒ 1 + 2PQ + PQ2 = 49 + PQ2
⇒ 2PQ = 48
⇒ PQ = 24 cm
⇒ OQ = 1 + PQ = 1 + 24 = 25 cm
Now, sin Q = OP/OQ = 7/25
cos Q = PQ/OQ = 24/25
So, sin Q + cos Q = (7/25) + (24/25) = 31/25
Therefore, the value of sin Q + cos Q is 31/25.