Home›MPPSC Forest›State Forest Service Mains Exam›Section 'B': Forestry and General Science›UNIT-10: Elementary Mathematics and General Mental Ability›Circular measure, definitions of trigonometric ratio, simple problems on height and distance›If in a triangle ABC, angle ABC = \frac{\pi}{2} and sides AB=12 and

If in a triangle ABC, angle ABC=π2ABC = \frac{\pi}{2}ABC=2π​ and sides AB=12 and BC = 5, then the value of sinC + cosA is:

20181M#mppsc-forest#pyq#mcq#2018
A.2413\frac{24}{13}1324​Correct
B.1213\frac{12}{13}1312​
C.512\frac{5}{12}125​
D.None of these
Explanation & Solution

Correct Answer: (A) 2413\frac{24}{13}1324​

In right-angled triangle ABC with ∠\angle∠ B = 90^∘\circ∘, AB = 12 and BC = 5, the hypotenuse AC = 122+52\sqrt{12^2 + 5^2}122+52​ = 13 by Pythagoras theorem. Then sin⁡\sinsin C = ABAC\frac{AB}{AC}ACAB​ = 1213\frac{12}{13}1312​ and cos⁡\coscos A = ABAC\frac{AB}{AC}ACAB​ = 1213\frac{12}{13}1312​, so sin⁡\sinsin C + cos⁡\coscos A = 1213\frac{12}{13}1312​ + 1213\frac{12}{13}1312​ = 2413\frac{24}{13}1324​.

हिंदी में प्रश्न एवं आदर्श उत्तर

यदि त्रिभुज ABC में, कोण ABC=π2ABC = \frac{\pi}{2}ABC=2π​ है तथा भुजायें AB=12 एवं BC = 5 हैं, तब sinC + cosA का मान है:

A.2413\frac{24}{13}1324​सही
B.1213\frac{12}{13}1312​
C.512\frac{5}{12}125​
D.इनमें से कोई नहीं

सही उत्तर: (A) 2413\frac{24}{13}1324​

समकोण त्रिभुज ABC में पाइथागोरस प्रमेय द्वारा कर्ण AC = 13 प्राप्त होता है। sin⁡\sinsin C = 1213\frac{12}{13}1312​ और cos⁡\coscos A = 1213\frac{12}{13}1312​ है, जिससे sin⁡\sinsin C + cos⁡\coscos A का मान 2413\frac{24}{13}1324​ होगा।

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