CBSE ADDA

CBSE MATH STUDY: Factor and reminder theorem :Polynomial class IX :  Proof of this factor theorem Let  p ( x ) be a polynomial of degree greater than or equal to one and  a   be  areal number such that  p ( a... Proof of this factor theorem Let  p ( x ) be a polynomial of degree greater than or equal to one and  a   be  areal number such that  p ( a ) = 0. Then, we have to show that ( x  –  a ) is a factor of  p ( x ). Let  q ( x ) be the quotient when  p ( x ) is divided by  ( x – a ). By remainder theorem, Dividend  = Divisor x Quotient + Remainder p ( x ) = ( x – a ) x  q ( x ) +  p ( a ) [Remainder theorem] ⇒   p ( x ) = ( x – a ) x  q ( x ) [ p ( a ) = 0] ⇒  ( x – a ) is a factor of  p ( x ) Conversely, let ( x – a ) be a factor of  p ( x ). Then we have to prove that  p ( a ) = 0 Now,     ( x – a ) is a factor of  p ( x ) ⇒   p ( x ), when divided by ( x – a ) gives remainder zero.  But, by the remainder theorem,  p ( x ) when divided by ( x – a ) gives the remainde

1-mark Questions/ Answers 1. What happens when magnesium ribbon burns in air? Ans. When magnesium ribbon burns in air, it combines with the oxygen to form magnesium oxide.  2Mg(s) + O2(g) ® 2MgO(s) 2. Name the gas evolved when zinc reacts with dil. HCl. Ans. Hydrogen gas is evolved. 3. What is a chemical equation? Ans. A chemical equation is a symbolic notation that uses formulae instead of words to represent a chemical equation. 4. On what chemical law, balancing of chemical equation is based? Ans. Balancing of a chemical equation is based on the law of conservation of mass. 5. Represent decomposition of ferrous sulphate with the help of balanced chemical equation. Ans. 2FeSO4(s) ® Fe2O3(s) + SO2(g) + SO3(g) 6. When carbon dioxide is passed through lime water, it turns milky, why? Ans. Lime water (calcium hydroxide) combines with carbon dioxide to form a suspension of calcium carbonate which makes lime water milky. Ca(OH)2 + CO2 ® CaCO3 + H2O 7. A zinc r

Q. What is Nutrients? Ans: The chemical present in food is called nutrients . Q. What are major components of foods? Ans: The major components nutrients are: carbohydrates,Fats,Vitamins,Proteins,Minerals,Roughage and Water Q. What are major nutrients of foods? Ans: carbohydrates, Fats, Vitamins , Proteins and Minerals Q. Name the components of food other than nutrients that are needed by our body. Ans: Components of food other than nutrients that are needed by our body are dietary fibers and water Q. What are fats? What are its types? Ans: Fats are energy giving nutrients comes from plants and animals. Fats comes from animal are called animal fats like milk cheese, butter etc. Fats comes from plants are called vegetable fats like fruit , coconut, soya beans etc Q. How fats are use full to us? Ans: Fats give us energy. Fats also protect skin from injury, heat and cold. fats also absorb vitamins from fats soluble vitamins. Q. why we do not eat excess fats? Ans: If we eat excess fat

chemistry adda: X Formative assessments Chemical reaction and equa... : Q1. The given equation represents the reaction of sodium metal with water. Sodium + Water Sodium hydroxide + Hydrogen Which of the followin...