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# State whether the following are true or false. Justify your answer. sec A = 12/5 for some value of angle A. - Mathematics

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#### Question

sec A = 12/5 for some value of angle A.

#### Solution

sec A =  12/5 Hypotenuse/Side adjacent to ∠A -  12/5

AC/AB = 12/5

Let AC be 12k, AB will be 5k, where k is a positive integer.

Applying Pythagoras theorem in ΔABC, we obtain

AC2 = AB2 + BC2

(12k)2 = (5k)2 + BC2

144k2 = 25k2 + BC2

BC2 = 119k2

BC = 10.9k

It can be observed that for given two sides AC = 12k and AB = 5k,

BC should be such that,

AC − AB < BC < AC + AB

12k − 5k < BC < 12k + 5k

7< BC < 17 k

However, BC = 10.9k. Clearly, such a triangle is possible and hence, such value of sec A is possible.

Hence, the given statement is true.

Is there an error in this question or solution?

#### APPEARS IN

NCERT Solution for Mathematics Textbook for Class 10 (2019 (Latest))
Chapter 8: Introduction to Trigonometry
Ex. 8.1 | Q: 11.2 | Page no. 181
RD Sharma Solution for Class 10 Maths (2018 (Latest))
Chapter 10: Trigonometric Ratios
Ex. 10.1 | Q: 36.2 | Page no. 26
RD Sharma Solution for Class 10 Maths (2018 (Latest))
Chapter 10: Trigonometric Ratios
Ex. 10.1 | Q: 36.2 | Page no. 26