In this article , some important algebra questions asked in SSC CGL previous year papers are discussed with explanations.
Sol. Given .
Squaring both sides we get,
(i) Now =
Putting , we get
2. If , then find the value of .
Sol. Cubing both the sides , we get
[ putting the value of ]
We can use the following formula directly
3. If then find the value of .
Adding 2 both sides we get . It can be written as
Taking +ve square root of both sides, we get
Again adding 2 both the sides we get
This implies . Hence
Now =3 ( from equ. (i) )
4. If then find the value of .
Sol. To solve the above question you can use the following formula
(i ) If then and
(ii) If then
Proof. (i ) Given
Squaring both sides we get
. Now subtracting 2 from both sides we get,
Similarly we can prove that If then
Now using the above formula the value of = .
5. If , then find the value of .
Sol. Dividing the given equation by , we get . This implies ………… (i)
On squaring both sides we get, . It gives ………………. (ii)
Now cubing both sides of eqiuation (i), we get . This implies …………….(iii)
squaring equation (ii) we get …………..(iv)
Now . This gives . Thus
On putting the value of from (iii), the value of
6. If , then what is the value of .
Sol. Given that .
Dividing by , we get . Now squaring both sides we get
. This implies .