Study Materials and Revision Notes for Ch 10 Circle Class 10th Maths
Circle• Circle: A circle is a locus of a point which moves in such a way that the distance from that point is always fixed.
• Radius: The constant distance from the centre to the circumference of the circle.
• Secant: A line which intersect the circle at two different points.
• Chord: Any line segment joining the two points on the circumference of the circle.
• Diameter: The longest distance between the two points on the circumference of the circle. It is the longest chord.
![](http://1.bp.blogspot.com/-GmBXptcrYv0/WHpOv7Hdv6I/AAAAAAAABtI/eUbFHzmZdM8lmZU4TVLadM0WPzKISWnnwCLcB/s1600/circle-class-10-notes-1.jpg)
Here, AO is the radius of the circle and AB is the diameter of the circle.
• Tangent: A line which touches the circle exactly at one point.
• For cubic polynomial: If α,β and γ are zeroes of polynomial p(x) = ax3 + bx2 + cx + d then:
(i) α + β + γ = -b/a = (-coefficient of x2)/(coefficient of x3)
(ii) αβ + βγ + γα = c/a = (constant term of x)/(coefficient of x3)
(iii) α.β.γ = -d/a = (-constant term)/(coefficient of x3)
(iv) A cubic polynomial whose zeroes are α, β and γ, is given by:
p(x) = k[x3 - (α+β+γ)x2 + (αβ+βγ+γα)x - αβγ] where k is any real number.
• Division Algorithm: If p(x) and g(x) are any two polynomials where g(x) ≠ 0, then we can find polynomials q(x) and r(x) such that:
p(x) = g(x) × q(x) + r(x), where r(x) = 0 or degree r(x) < degree g(x).
(i) α + β + γ = -b/a = (-coefficient of x2)/(coefficient of x3)
(ii) αβ + βγ + γα = c/a = (constant term of x)/(coefficient of x3)
(iii) α.β.γ = -d/a = (-constant term)/(coefficient of x3)
(iv) A cubic polynomial whose zeroes are α, β and γ, is given by:
p(x) = k[x3 - (α+β+γ)x2 + (αβ+βγ+γα)x - αβγ] where k is any real number.
• Division Algorithm: If p(x) and g(x) are any two polynomials where g(x) ≠ 0, then we can find polynomials q(x) and r(x) such that:
p(x) = g(x) × q(x) + r(x), where r(x) = 0 or degree r(x) < degree g(x).