1 | 1 | |||
Wiedząc, że x≠0 i x2+ | =a oraz a≥2 wykaż, że x10+ | =a5−5a3+5a | ||
x2 | x10 |
1 | 1 | |||
oraz (x2+ | )2=x4+ | +2=a2. | ||
x2 | x4 |
1 | ||
1) podnieść stronami do trzeciej potęgi x2+ | =a i po przekształceniach otrzymać | |
x2 |
1 | ||
x6+ | =a3−3a | |
x6 |
1 | 1 | 1 | ||||
a5=x10+ | +5(x6+ | )+10a=x10+ | +5a3−15a+10a | |||
x10 | x6 | x10 |
1 | ||
x2 + | = a / 3 | |
x2 |
1 | 1 | |||
x6 + | + 3(x2 + | ) = a3 | ||
x6 | x2 |
1 | ||
x6 + | = a3 − 3a | |
x6 |
1 | ||
(1) x2 + | = a / 2 | |
x2 |
1 | ||
x4 + | = a2 − 2 / 2 | |
x4 |
1 | ||
x8 + | = a4 − 4a2 + 2 / * równanie (1) | |
x8 |
1 | 1 | |||
x10 + | + x6 + | = a5 − 4a3 + 2a | ||
x10 | x6 |
1 | ||
x10 + | = a5 − 5a3 + 5a | |
x10 |