Advertisements
Advertisements
प्रश्न
Solve the equation 3x² – x – 7 = 0 and give your answer correct to two decimal places.
Advertisements
उत्तर
3x² – x – 7 = 0
a = 3, b = -1, c = -7
x = `(-b ± sqrt(b^2 - 4ac))/(2a)`
= `-((-1) ± sqrt((-1)^2 - 4.3. (-7)))/(2 xx 3)`
= `(1 ± sqrt(1 + 84))/(6)`
= `( 1 ± sqrt(85))/(6)`
= `(1 ± 9·216)/(6)`
x = `( 1 + 9.216)/(6) and (1 - 9.216)/(6)`
= `(10.216)/(6) and -(8.216)/(6)`
= 1·703 and -1·37.
संबंधित प्रश्न
Find the roots of the following quadratic equation by factorisation:
100x2 – 20x + 1 = 0
An aeroplane take 1 hour less for a journey of 1200 km if its speed is increased by 100 km/hr from its usual speed. Find its usual speed.
The hypotenuse of a right triangle is 25 cm. The difference between the lengths of the other two sides of the triangle is 5 cm. Find the lengths of these sides.
A piece of cloth costs Rs. 35. If the piece were 4 m longer and each meter costs Rs. 1 less, the cost would remain unchanged. How long is the piece?
Solve the given quadratic equation for x : 9x2 – 9(a + b)x + (2a2 + 5ab + 2b2) = 0 ?
One of the roots of equation 5m2 + 2m + k = 0 is `(-7)/5` Complete the following activity to find the value of 'k'.
Show that x = −3 is a solution of x2 + 6x + 9 = 0.
The sum of the square of 2 positive integers is 208. If the square of larger number is 18 times the smaller number, find the numbers.
Solve the following equation by factorization
6p2+ 11p – 10 = 0
At t minutes past 2 pm, the time needed by the minutes hand of a clock to show 3 pm was found to be 3 minutes less than `t^2/4` minutes. Find t.
