Question

In ΔABC, if m∠ A = m∠C, m∠ B= ß (where ß is an acute angle), and BC = x, which expression gives the length of b, the side opposite ∠B?

choices -
A. $\sqrt{x^{2}-2x^{2}cos\beta }$
B. $\sqrt{x^{2}-(1-cos\beta)}$
C. $\sqrt{2x^{2}(1-cos\beta)^{2} }$
D. $\sqrt{2x^{2}(1-cos\beta)}$

Answer 1

Answer:

B is ur solution...

hope it helps you

Answer 2

Answer:

D)..

Step-by-step explanation:

D. \sqrt{2x^2(1-cos} \beta) is the length of  b, the side opposite to \angle B.

Explanation:

According to the line of cosines, length of one side when opposite angle and two other sides are given.

c^2=a^2+b^2-2 ab cos C, where a,b, c are the sides of triangle while C is the opposite angle of side c.

Here, a=b=x(because \angle A= \angle C) , c= length of b (that is side AC) and C= \angle B= \beta