why some times with price of a good change the demand curve

why some times with price of a good change, the demand curve shift out/ in, and sometimes the demand curve change angle when price of the good change ?

Solution

A CHANGE IN THE PRICE OF GOODS WILL RESULT IN A MOVEMENT OALONG A DEMAND CURVE. EVEN A CHANGE IN NON-PRICE VARIABLE WILL RESULT IN A SHIFT IN THE DEMAND CURVE. FOR A NORMAL GOOD, IF INCOME RAISES, AN OUTWARD SHIFT IN DEMAND CURVE OCCURS. FOR AN INFERIROR GOOD, IF INCOME DECLINES, AN INWARD SHIFT IN DEMAND CURVE OCCURS MOVEMENTS ALONG THE DEMAND CURVE ARE DUE TO A CHANGE IN THE PRICE OF A GOOD, THE PRICE OF A SUBSTITUTE. IF THE PRICE OF A GOOD OR SERVICE CHANGES THE CONSUMER WILL ADJUST THE QUANTITY DEMANDED BASED ON THE PREFERENCES, INCOME AND PRICES OF OTHER FACTORS SHIFTS IN THE DEMAND CURVE ARE RELATED TO NON-PRICE EVENTS THAT INCLUDE INCOME, PREFERENCES AND THE PRICE OF SUBSTITUTES AND COMPLEMENTS GOODS. A CHANGE IN PREFERENCES COULD RESULT IN AN INCREASE (OUTWARD SHIFT) OR DECREASE (INWARD SHIFT) IN THE QUANTITY LEVEL DESIRED FOR A SPECIFIC PRICE; WHILE A CHANGE IN THE PRICE OF A SUBSTITUTE, COULD RESULT IN AN OUTWARD SHIFT IF THE PRICE OF THE SUBSTITUTE INCREASES AND AN INWARD SHIFT IF THE SUBSTITUTE\'S PRICE DECREASES. THE DEMAND CURVE FOR A GOOD WILL SHIFT IN PARALLEL WITH A SHIFT IN THE DEMAND FOR A COMPLEMENT GOODS      .