English

13 X 2 + 7 X + 1 = 0 - Mathematics

Advertisements
Advertisements

Question

\[13 x^2 + 7x + 1 = 0\]

Advertisements

Solution

Given: 

\[13 x^2 + 7x + 1 = 0\]

Comparing the given equation with the general form of the quadratic equation 

\[a x^2 + bx + c = 0\], we get 
\[a = 13, b = 7\]  and \[c = 1\] .
Substituting these values in 
\[\alpha = \frac{- b + \sqrt{b^2 - 4ac}}{2a}\] and \[\beta = \frac{- b - \sqrt{b^2 - 4ac}}{2a}\],we get:
\[\alpha = \frac{- 7 + \sqrt{49 - 4 \times 13 \times 1}}{2 \times 13}\] and \[\beta = \frac{- 7 - \sqrt{49 - 4 \times 13 \times 1}}{2 \times 13}\]
\[\Rightarrow \alpha = \frac{- 7 + \sqrt{49 - 52}}{26}\]   and   \[\beta = \frac{- 7 - \sqrt{49 - 52}}{26}\]
\[\Rightarrow \alpha = \frac{- 7 + \sqrt{- 3}}{26}\] and \[\beta = \frac{- 7 - \sqrt{- 3}}{26}\]
\[\Rightarrow \alpha = \frac{- 7 + i\sqrt{3}}{26}\] and \[\beta = \frac{- 7 - i\sqrt{3}}{26}\]
\[\Rightarrow \alpha = - \frac{7}{26} + \frac{\sqrt{3}}{26}i\] and   \[\beta = - \frac{7}{26} - \frac{\sqrt{3}}{26}i\]
Hence, the roots of the equation are  
\[- \frac{7}{26} \pm \frac{\sqrt{3}}{26}i .\]
shaalaa.com
  Is there an error in this question or solution?
Chapter 14: Quadratic Equations - Exercise 14.1 [Page 6]

APPEARS IN

RD Sharma Mathematics [English] Class 11
Chapter 14 Quadratic Equations
Exercise 14.1 | Q 18 | Page 6
Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×