Question

ICSE Mathematics for Class 9
8. From the adjoining figure find the values of the following:
(a) sin B
(b) cos C
(c) sec B
(d) tan B + tan C
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Answer 1

Answer:

Step-by-step explanation:

(a) Sin B = oppisite side from angle B / hypotenuse

       so, hypotenuse would be

      AB^2= AD^2+ BD^2

               = 4 + 9 = 13 so hypotenuse is $\sqrt{13$ cm

SinB = 2/$\sqrt{13$

(b) cos C = adjacent side from angle C/ hypotenuse

so the next hypotenuse would be similarly

2$\sqrt{5$ cm

cos C= 4/ 2$\sqrt{5$

cos C = 2/$\sqrt{5$

(c) secB = hypotenuse/ adjacent side from angle B

secB = $\sqrt{13$/ 3 cm

(d) tanB + tan C = 2/3 + 2/4 = 1/2