February 4, 1982

THE economy is rocky and the price of hotel rooms is beyond many budgets, but New York continues to be a magnet for the rest of the country and, indeed, the world. To an increasing number of visitors the solution is simple: stay with a friend. For New Yorkers, no matter how hospitably minded, it isn't quite so easy. Large apartments are the exception rather than the norm, and the scale and price of many newer apartments precludes nonessential space. Most brownstones, once occupied by single families, have been broken into individual apartments. Manhattan residents would agree that space has become one of the city's great luxuries. Nevertheless, New Yorkers are an ingenious lot, and rather than forgo the pleasure of seeing friends from out of town, many have come up with sleeping facilities scarcely larger than the size of a reclining body. Others, more traditionally minded, have put convertible sleep sofas in rooms ranging from libraries and dining rooms to home offices.

The Eastman Kodak Company yesterday introduced a line of cameras that use a film disk instead of conventional roll film. The new products are intended to secure the company's position as the dominant force in amateur photography for the rest of the decade. Foreshadowed in patent drawings and research disclosures during the past few years, the introduction included no surprises but was still impressive, according to industry analysts. The disk cameras are ''the biggest innovation in amateur photography since the cartridge-loading Instamatic was introduced 19 years ago,'' Walter Fallon, the company's chairman, unabashedly told reporters gathered at the Plaza Hotel yesterday. The meeting was one of eight news conferences the company held around the world.

President Hosni Mubarak of Egypt told President Reagan today that solving the Palestinian problem was the ''key to peace'' in the Middle East. He said the Palestinians could not be denied ''the right to self-determination'' and formation of ''a national entity.'' In formal remarks at the White House, marking his first visit here since becoming President after the assassination of Anwar el-Sadat last October, Mr. Mubarak did not mention the negotiations with Israel for self-rule for Palestinians living in the occupied West Bank and Gaza Strip. Nor did he mention the Camp David agreements of 1978 that led to the 1979 peace treaty between Egypt and Israel and the talks on self-rule.

Governor Carey plans to ask the Legislature to increase the state's sales tax to provide more money for education, top aides to the Governor said today. But they said he would link his request to changes in the income tax designed to provide relief for New Yorkers with low incomes, Word of the proposal came as Mr. Carey's Commerce Commissioner, George Dempster, gave a speech in New York City calling for incometax reductions and Assembly Speaker Stanley Fink called on the Legislature to enact income-tax cuts this year that would take effect later in the decade. Mr. Carey, in the meantime, held a news conference at which he said that while the state could not afford tax reductions in its current budget, he would not be opposed to ''down-range'' income-tax cuts. Help for Poor Districts The increased spending for education is aimed at reducing disparities between rich and poor school districts, as required in a series of court decisions involving the school district in Levittown, L.I., and other districts in the state.

Congress appears to be increasingly divided over the decision to send more aid to El Salvador, but for the moment the Administration seems to have majority support for its policy of trying to prevent the overthrow of the Salvadoran Government. At a news conference today, Speaker Thomas P. O'Neill Jr. said, ''I hear some rising objections to what Haig is doing from within the Democratic Party and from my area at home.'' But his fellow Democrat, Representative Jim Wright of Texas, the majority leader, said in an interview, ''I agree with the Administration position, and I very actively oppose any effort to withhold assistance to the moderate Government of Duarte.'' Two Unappealing Choices Perhaps the most frequent reaction on Capitol Hill, however, was expressed by Senator J. James Exon, Democrat of Nebraska, who said the United States had two unappealing choices. ''If we turn down the additional aid,'' he said, ''we could be helping the Communist guerrilla takeover of the country. But on the other hand, we'd be aiding a Government we're not happy with. The bottom line is, which is the lesser of two evils?''