How to solve 

Ex 3.1 

Q 15. If a + 1 / a = 3 ,find

(1) a2  + 1/a2 

(2) a4 + 1/a4 

Asked by prathameshbhantar09.9spicertl | 13th Jul, 2020, 06:21: PM

Expert Answer:

Given: a + 1/a = 3
 
left parenthesis 1 right parenthesis
straight a squared plus 1 over straight a squared equals open parentheses straight a plus 1 over straight a close parentheses squared minus 2 equals open parentheses 3 close parentheses squared minus 2 equals 9 minus 2 equals 7

left parenthesis 2 right parenthesis
straight a to the power of 4 plus 1 over straight a to the power of 4 equals open parentheses straight a squared plus 1 over straight a squared close parentheses squared minus 2 equals open parentheses 7 close parentheses squared minus 2 equals 49 minus 2 equals 47

Answered by Renu Varma | 14th Jul, 2020, 11:38: AM