Question

4. Starting from (-1) × 5, write various products showing some pattern to show
(-1)× (-1)=1.​

Answer 1

Answer:

SOME IMPORTANT FORMULAS AND IDENTITY:-

1. (α+в)²= α²+2αв+в²

2. (α+в)²= (α-в)²+4αв

3. (α-в)²= α²-2αв+в² he

4. (α-в)²= (α+в)²-4αв

5. α² + в²= (α+в)² - 2αв.

6. α² + в²= (α-в)² + 2αв.

7. α²-в² =(α + в)(α - в)

8. 2(α² + в²) = (α+ в)² + (α - в)²

9. 4αв = (α + в)² -(α-в)²

10. αв ={(α+в)/2}²-{(α-в)/2}²

11. (α + в + ¢)² = α² + в² + ¢² + 2(αв + в¢ + ¢α)

12. (α + в)³ = α³ + 3α²в + 3αв² + в³

13. (α + в)³ = α³ + в³ + 3αв(α + в)

14. (α-в)³=α³-3α²в+3αв²-в³

15. α³ + в³ = (α + в) (α² -αв + в²)

16. α³ + в³ = (α+ в)³ -3αв(α+ в)

17. α³ -в³ = (α -в) (α² + αв + в²)

18. α³ -в³ = (α-в)³ + 3αв(α-в)