Question

please solve the 6th question
it is urgent​

Answer 1

Answer:

Thanks for your question...

Your required answer :

• $cos \: a \: = \frac{ac}{ab} - - - - (1)$

Similarly :

• $cos \: b = \frac{bc}{ab} - - - - (2)$

It is given that :

• cos a = cos b

Therefore :

$\frac{ac}{ab} = \frac{bc}{ab}$

---→ So , ac = BC

We know that in triangle , angles opposite to equal sides are also equal.

Thus , angle A = Angle B

• Hence Proved

Answer 2

Given :-

∠A and ∠B are acute angle such that cos A = cos B

To Show :-

∠A = ∠B

Solution :-

We know that

cos θ = Adj/Hyp

Now,

In ΔABC

⇒ cos A = AC/AB

⇒ cos B = BC/AB

cos A = cos B (Given)

⇒ AC/AB = BC/AB

⇒ AC = BC

Now

We know that in a triangle the angle which is opposite to equal sides are always equal

∴ ∠A = ∠B

Hence, proved